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| United States Patent Application |
20090286767
|
| Kind Code
|
A1
|
|
Bakthavatchalam; Rajagopal
;   et al.
|
November 19, 2009
|
SUBSTITUTED QUINOLIN-4-YLAMINE ANALOGUES
Abstract
Substituted quinolin-4-ylamine analogues are provided. Such compounds are
ligands that may be used to modulate specific receptor activity in vivo
or in vitro, and are particularly useful in the treatment of conditions
associated with pathological receptor activation in humans, domesticated
companion animals and livestock animals. Pharmaceutical compositions and
methods for using them to treat such disorders are provided, as are
methods for using such ligands for receptor localization studies.
| Inventors: |
Bakthavatchalam; Rajagopal; (Madison, CT)
; Caldwell; Timothy M.; (Guilford, CT)
; Chenard; Bertrand L.; (Waterford, CT)
; De Lombaert; Stephane; (Madison, CT)
; Hodgetts; Kevin J.; (Killingworth, CT)
|
| Correspondence Address:
|
EDWARD ANGELL PALMER & DODGE, LLP
P.O. BOX 55874
BOSTON
MA
02205
US
|
| Assignee: |
Neurogen Corporation
Branford
CT
|
| Serial No.:
|
368302 |
| Series Code:
|
12
|
| Filed:
|
February 9, 2009 |
| Current U.S. Class: |
514/210.21; 435/375; 514/234.5; 514/235.2; 514/252.04; 514/255.05; 514/275; 514/293; 514/300; 514/313; 544/127; 544/128; 544/238; 544/331; 544/405; 546/122; 546/160; 546/83 |
| Class at Publication: |
514/210.21; 435/375; 514/234.5; 514/235.2; 514/252.04; 514/255.05; 514/275; 514/293; 514/300; 514/313; 544/127; 544/128; 544/238; 544/331; 544/405; 546/83; 546/122; 546/160 |
| International Class: |
A61K 31/397 20060101 A61K031/397; C12N 5/00 20060101 C12N005/00; A61K 31/5377 20060101 A61K031/5377; A61K 31/501 20060101 A61K031/501; A61K 31/497 20060101 A61K031/497; A61K 31/506 20060101 A61K031/506; A61K 31/4375 20060101 A61K031/4375; A61K 31/4709 20060101 A61K031/4709; C07D 413/14 20060101 C07D413/14; C07D 405/14 20060101 C07D405/14; C07D 401/14 20060101 C07D401/14; C07D 401/10 20060101 C07D401/10; A61P 3/04 20060101 A61P003/04; A61P 29/00 20060101 A61P029/00 |
Claims
1. A compound of the formula: ##STR00250## or a pharmaceutically
acceptable salt thereof, wherein:at least one of Y and Z is N; and the
other of Y and Z is N or CR.sub.1;R.sub.1 is hydrogen, halogen, cyano,
amino, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4haloalkyl,
C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4haloalkoxy or mono- or
di-(C.sub.1-C.sub.4alkyl)amino;R.sub.2 is: (i) hydrogen, halogen or
cyano;(ii) a group of the formula --R.sub.c-M-A-R.sub.y, wherein:R.sub.c
is C.sub.0-C.sub.3alkyl or is joined to R.sub.y or R.sub.z, to form a 4-
to 10-membered carbocycle or heterocycle that is substituted with from 0
to 2 substituents independently chosen from R.sub.b;M is a single
covalent bond, O, S, SO.sub.2, C(.dbd.O), OC(.dbd.O), C(.dbd.O)O,
O--C(.dbd.O)O, C(.dbd.O)N(R.sub.z), OC(.dbd.O)N(R.sub.z),
N(R.sub.z)C(.dbd.O), N(R.sub.z)SO.sub.2, SO.sub.2N(R.sub.z) or
N(R.sub.z);A is a single covalent bond or C.sub.1-C.sub.8alkyl
substituted with from 0 to 3 substituents independently chosen from
R.sub.b; andR.sub.y and R.sub.z, if present, are:(a) independently
hydrogen, C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkyl ether,
C.sub.2-C.sub.8alkenyl, a 4-to 10-membered carbocycle or heterocycle, or
joined to R.sub.c to form a 4- to 10-membered carbocycle or heterocycle,
wherein each non-hydrogen R.sub.y and R.sub.z is substituted with from 0
to 6 substituents independently chosen from R.sub.b; or(b) joined to form
a 4- to 10-membered carbocycle or heterocycle that is substituted with
from 0 to 6 substituents independently chosen from R.sub.b;such that
R.sub.2 is not --NH.sub.2; or(iii) taken together with R.sub.7 to form a
fused 5- to 7-membered ring that is substituted with from 0 to 3
substituents independently chosen from oxo and
C.sub.1-C.sub.4alkyl;R.sub.7 is hydrogen, COOH, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4alkoxycarbonyl or taken together
with R.sub.2 to form a fused, optionally substituted ring;Ar.sub.1 is
phenyl or 6-membered heteroaryl, each of which is unsubstituted or
substituted ortho to the point of attachment with 1 or 2 substituents
independently chosen from groups of the formula LR.sub.a;Ar.sub.2 is 6-
to 10-membered aryl or 5- to 10-membered heteroaryl, each of which is
substituted with from 0 to 6 substituents independently chosen from oxo
and groups of the formula LR.sub.a;L is independently selected at each
occurrence from a single covalent bond, O, C(.dbd.O), OC(.dbd.O),
C(.dbd.O)O, OC(.dbd.O)O, S(O).sub.m, N(R.sub.x), C(.dbd.O)N(R.sub.x),
N(R.sub.x)C(.dbd.O), N(R.sub.x)S(O).sub.m, S(O).sub.mN(R.sub.x) and
N[S(O).sub.mR.sub.w]S(O).sub.m; wherein m is independently selected at
each occurrence from 0, 1 and 2; R.sub.x is independently selected at
each occurrence from hydrogen, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6alkanoyl and C.sub.1-C.sub.6alkylsulfonyl; and R.sub.w is
hydrogen or C.sub.1-C.sub.6alkyl;R.sub.a is independently selected at
each occurrence from:(i) hydrogen, halogen, cyano and nitro; and(ii)
C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl,
C.sub.1-C.sub.8haloalkyl, C.sub.2-C.sub.8alkyl ether, mono- and
di-(C.sub.1-C.sub.8alkyl)amino and (3- to 10-membered
heterocycle)C.sub.0-C.sub.6alkyl, each of which is substituted with from
0 to 6 substituents independently selected from R.sub.b; andR.sub.b is
independently chosen at each occurrence from hydroxy, halogen, amino,
aminocarbonyl, cyano, nitro, oxo, COOH, C.sub.1-C.sub.8alkyl,
C.sub.1-C.sub.8alkoxy, C.sub.1-C.sub.8alkylthio, C.sub.1-C.sub.8alkanoyl,
C.sub.1-C.sub.8alkanoyloxy, C.sub.1-C.sub.8alkoxycarbonyl,
C.sub.1-C.sub.8alkyl ether, C.sub.1-C.sub.8hydroxyalkyl,
C.sub.1-C.sub.8haloalkyl, phenylC.sub.0-C.sub.8alkyl, mono- and
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl,
C.sub.1-C.sub.8alkylsulfonyl and (4- to 7-membered
heterocycle)C.sub.0-C.sub.8alkyl.
2. A compound or salt according to claim 1, wherein Z is N.
3. A compound or salt according to claim 1, wherein Y is N.
4. A compound or salt according to claim 2, wherein Y is CH.
5. A compound or salt according to claim 1, wherein Y and Z are N.
6. A compound or salt according to claim 1, wherein Ar.sub.2 is phenyl or
a 6-membered heteroaryl, each of which is substituted with from 0 to 3
substituents independently selected from (a) groups of the formula
LR.sub.a and (b) groups that are taken together to form a fused, 5- to
7-membered heterocyclic ring that is substituted with from 0 to 3
substituents independently selected from R.sub.b.
7. (canceled)
8. (canceled)
9. A compound or salt according to claim 6, wherein Ar.sub.1 is phenyl,
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
unsubstituted or substituted with halogen, cyano, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy or
C.sub.1-C.sub.6haloalkoxy.
10. A compound or salt according to claim 9, wherein:Ar.sub.1 is phenyl,
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl substituted with halogen,
cyano, C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4haloalkyl; andAr.sub.2 is
phenyl, pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
substituted with halogen, cyano, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4hydroxyalkyl, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkylsulfonyl or
C.sub.1-C.sub.4haloalkylsulfonyl.
11. A compound or salt according to claim 1, wherein R.sub.2 is:(i)
hydrogen, hydroxy or halogen; or(ii) C.sub.1-C.sub.6alkyl,
(C.sub.3-C.sub.7cycloalkyl)C.sub.0-C.sub.4alkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.1-C.sub.6hydroxyalkyl,
C.sub.2-C.sub.6alkyl ether, mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl or (4- to 7-membered
heterocycloalkyl)C.sub.0-C.sub.4alkyl, each of which is substituted with
from 0 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.6haloalkyl.
12.-16. (canceled)
17. A compound of the formula: ##STR00251## or a pharmaceutically
acceptable salt thereof, wherein:Y and Z are each independently N or
CR.sub.1;R.sub.1 is independently selected at each occurrence from
hydrogen, halogen, cyano, amino, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6haloalkoxy and mono- and
di-(C.sub.1-C.sub.6alkyl)amino;R.sub.2 is: (i) hydrogen, halogen or
cyano;(ii) a group of the formula --R.sub.c-M-A-R.sub.Y, wherein:R.sub.c
is C.sub.0-C.sub.3alkyl or is joined to R.sub.y or R.sub.z, to form a 4-
to 10-membered carbocycle or heterocycle that is substituted with from 0
to 2 substituents independently chosen from R.sub.b;M is a single
covalent bond, O, S, SO.sub.2, C(.dbd.O), OC(.dbd.O), C(.dbd.O)O,
O--C(.dbd.O)O, C(.dbd.O)N(R.sub.z), OC(.dbd.O)N(R.sub.z),
N(R.sub.z)C(.dbd.O), N(R.sub.z)SO.sub.2, SO.sub.2N(R.sub.z) or
N(R.sub.z);A is a single covalent bond or C.sub.1-C.sub.8alkyl
substituted with from 0 to 3 substituents independently chosen from
R.sub.b; andR.sub.y and R.sub.z, if present, are:(a) independently
hydrogen, C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkyl ether,
C.sub.2-C.sub.8alkenyl, a 4-to 10-membered carbocycle or heterocycle, or
joined to R.sub.c to form a 4- to 10-membered carbocycle or heterocycle,
wherein each non-hydrogen R.sub.y and R.sub.z is substituted with from 0
to 6 substituents independently chosen from R.sub.b; or(b) joined to form
a 4- to 10-membered carbocycle or heterocycle that is substituted with
from 0 to 6 substituents independently chosen from R.sub.b; or(iii) taken
together with R.sub.7 to form a fused 5- to 7-membered ring that is
substituted with from 0 to 3 substituents independently chosen from oxo
and C.sub.1-C.sub.4alkyl;R.sub.7 is hydrogen, COOH, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6alkoxy, C.sub.1-C.sub.6alkoxycarbonyl or taken together
with R.sub.2 to form a fused, optionally substituted ring;Ar.sub.1 is
phenyl or 6-membered heteroaryl, each of which is unsubstituted or
substituted ortho to the point of attachment with 1 or 2 substituents
independently chosen from groups of the formula LR.sub.a;Ar.sub.2 is 5-
to 10-membered heteroaryl that is substituted with from 0 to 6
substituents independently chosen from oxo and groups of the formula
LR.sub.a;L is independently selected at each occurrence from a single
covalent bond, O, C(.dbd.O), OC(.dbd.O), C(.dbd.O)O, OC(.dbd.O)O,
S(O).sub.m, N(R.sub.x), C(.dbd.O)N(R.sub.x), N(R.sub.x)C(.dbd.O),
N(R.sub.x)S(O).sub.m, S(O).sub.mN(R.sub.x) and
N[S(O).sub.mR.sub.w]S(O).sub.m; wherein m is independently selected at
each occurrence from 0, 1 and 2; R.sub.x is independently selected at
each occurrence from hydrogen, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6alkanoyl and C.sub.1-C.sub.6alkylsulfonyl; and R.sub.w is
hydrogen or C.sub.1-C.sub.6alkyl;R.sub.a is independently selected at
each occurrence from:(i) hydrogen, halogen, cyano and nitro; and(ii)
C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl,
C.sub.1-C.sub.8haloalkyl, C.sub.2-C.sub.8alkyl ether, mono- and
di-(C.sub.1-C.sub.8alkyl)amino and (3- to 10-membered
heterocycle)C.sub.0-C.sub.6alkyl, each of which is substituted with from
0 to 6 substituents independently selected from R.sub.b; andR.sub.b is
independently chosen at each occurrence from hydroxy, halogen, amino,
aminocarbonyl, cyano, nitro, oxo, COOH, C.sub.1-C.sub.8alkyl,
C.sub.1-C.sub.8alkoxy, C.sub.1-C.sub.8alkylthio, C.sub.1-C.sub.8alkanoyl,
C.sub.1-C.sub.8alkanoyloxy, C.sub.1-C.sub.8alkoxycarbonyl,
C.sub.1-C.sub.8alkyl ether, C.sub.1-C.sub.8hydroxyalkyl,
C.sub.1-C.sub.8haloalkyl, phenylC.sub.0-C.sub.8alkyl, mono- and
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl,
C.sub.1-C.sub.8alkylsulfonyl and (4- to 7-membered
heterocycle)C.sub.0-C.sub.8alkyl.
18.-26. (canceled)
27. A compound of the formula: ##STR00252## or a pharmaceutically
acceptable salt thereof, wherein:Y and Z are each independently N or
CR.sub.1;R.sub.1 is independently selected at each occurrence from
hydrogen, halogen, cyano, amino, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6haloalkoxy and mono- and
di-(C.sub.1-C.sub.6alkyl)amino;R.sub.2 is: (i) halogen or cyano;(ii) a
group of the formula --R.sub.c-M-A-R.sub.y, wherein:R.sub.c is
C.sub.0-C.sub.3alkyl or is joined to R.sub.y or R.sub.z, to form a 4- to
10-membered carbocycle or heterocycle that is substituted with from 0 to
2 substituents independently chosen from R.sub.b;M is a single covalent
bond, O, S, SO.sub.2, C(.dbd.O), OC(.dbd.O), C(.dbd.O)O, O--C(.dbd.O)O,
C(.dbd.O)N(R.sub.z), OC(.dbd.O)N(R.sub.z), N(R.sub.z)C(.dbd.O),
N(R.sub.z)SO.sub.2, SO.sub.2N(R.sub.z) or N(R.sub.z);A is a single
covalent bond or C.sub.1-C.sub.8alkyl substituted with from 0 to 3
substituents independently chosen from R.sub.b; andR.sub.y and R.sub.z,
if present, are:(a) independently hydrogen, C.sub.1-C.sub.8alkyl,
C.sub.2-C.sub.8alkyl ether, C.sub.2-C.sub.8alkenyl, a 4-to 10-membered
carbocycle or heterocycle, or joined to R.sub.c to form a 4- to
10-membered carbocycle or heterocycle, wherein each non-hydrogen R.sub.y
and R.sub.z is substituted with from 0 to 6 substituents independently
chosen from R.sub.b; or(b) joined to form a 4- to 10-membered carbocycle
or heterocycle that is substituted with from 0 to 6 substituents
independently chosen from R.sub.b; such that R.sub.2 is not --NH.sub.2;
or(iii) taken together with R.sub.7 to form a fused 5- to 7-membered ring
that is substituted with from 0 to 3 substituents independently chosen
from oxo and C.sub.1-C.sub.4alkyl;R.sub.7 is hydrogen, COOH,
C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6alkoxycarbonyl or taken together with R.sub.2 to form a
fused, optionally substituted ring;Ar.sub.1 is phenyl or 6-membered
heteroaryl, each of which is unsubstituted or substituted ortho to the
point of attachment with 1 or 2 substituents independently chosen from
groups of the formula LR.sub.a;Ar.sub.2 is 6- to 10-membered aryl or 5-
to 10-membered heteroaryl, each of which is substituted with from 0 to 6
substituents independently chosen from oxo and groups of the formula
LR.sub.a;L is independently selected at each occurrence from a single
covalent bond, O, C(.dbd.O), OC(.dbd.O), C(.dbd.O)O, OC(.dbd.O)O,
S(O).sub.m, N(R.sub.x), C(.dbd.O)N(R.sub.x), N(R.sub.x)C(.dbd.O),
N(R.sub.x)S(O).sub.m, S(O).sub.mN(R.sub.x) and
N[S(O).sub.mR.sub.w]S(O).sub.m; wherein m is independently selected at
each occurrence from 0, 1 and 2; R.sub.x is independently selected at
each occurrence from hydrogen, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6alkanoyl and C.sub.1-C.sub.6alkylsulfonyl; and R.sub.w is
hydrogen or C.sub.1-C.sub.6alkyl;R.sub.a is independently selected at
each occurrence from:(i) hydrogen, halogen, cyano and nitro; and(ii)
C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl,
C.sub.1-C.sub.8haloalkyl, C.sub.2-C.sub.8alkyl ether, mono- and
di-(C.sub.1-C.sub.8alkyl)amino and (3- to 10-membered
heterocycle)C.sub.0-C.sub.6alkyl, each of which is substituted with from
0 to 6 substituents independently selected from R.sub.b; andR.sub.b is
independently chosen at each occurrence from hydroxy, halogen, amino,
aminocarbonyl, cyano, nitro, oxo, COOH, C.sub.1-C.sub.8alkyl,
C.sub.1-C.sub.8alkoxy, C.sub.1-C.sub.8alkylthio, C.sub.1-C.sub.8alkanoyl,
C.sub.1-C.sub.8alkanoyloxy, C.sub.1-C.sub.8alkoxycarbonyl,
C.sub.1-C.sub.8alkyl ether, C.sub.1-C.sub.8hydroxyalkyl,
C.sub.1-C.sub.8haloalkyl, phenylC.sub.0-C.sub.8alkyl, mono- and
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl,
C.sub.1-C.sub.8alkylsulfonyl and (4- to 7-membered
heterocycle)C.sub.0-C.sub.8alkyl.
28. A compound or salt according to claim 27, wherein at least one of Y
and Z is N.
29. A compound or salt according to claim 27, wherein Y and Z are both CH.
30. A compound or salt according to claim 27, wherein Ar.sub.2 is phenyl
or a 6-membered heteroaryl, each of which is substituted with from 0 to 3
substituents independently selected from (a) groups of the formula
LR.sub.a and (b) groups that are taken together to form a fused, 5- to
7-membered heterocyclic ring that is substituted with from 0 to 3
substituents independently selected from R.sub.b.
31. (canceled)
32. (canceled)
33. A compound or salt according to claim 27, wherein Ar.sub.1 is phenyl,
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
unsubstituted or substituted with halogen, cyano, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy or
C.sub.1-C.sub.6haloalkoxy.
34.-46. (canceled)
47. A compound or salt according to claim 27, wherein the compound has the
formula: ##STR00253## wherein:Ar.sub.1 is phenyl, pyridyl, pyrimidinyl,
pyrazinyl or pyridazinyl, each of which is unsubstituted or substituted
with halogen, cyano, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6haloalkyl,
C.sub.1-C.sub.6alkoxy or C.sub.1-C.sub.6haloalkoxy;Ar.sub.2 is phenyl or
a 6-membered heteroaryl, each of which is substituted with from 0 to 3
substituents independently selected from (a) groups of the formula
LR.sub.a and (b) groups that are taken together to form a fused, 5- to
7-membered heterocyclic ring that is substituted with from 0 to 3
substituents independently selected from R.sub.b;R.sub.3 is selected
from:(i) hydrogen; and(ii) C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl,
C.sub.2-C.sub.8alkynyl, C.sub.6-C.sub.10arylC.sub.0-C.sub.8alkyl, and 5-
to 10-membered heterocycleC.sub.0-C.sub.8alkyl, each of which is
substituted with from 0 to 6 substituents independently selected from
R.sub.b;R.sub.5 and R.sub.6 are, independently at each occurrence:(i)
each independently selected from hydrogen, hydroxy and
C.sub.1-C.sub.6alkyl; or(ii) taken together to form a keto group; andn is
1, 2 or 3.
48. A compound or salt according to claim 47, wherein Ar.sub.2 is phenyl,
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
substituted with 0, 1 or 2 substituents independently selected from
halogen, cyano, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6haloalkyl,
C.sub.1-C.sub.6hydroxyalkyl, C.sub.1-C.sub.6alkyl ether,
C.sub.1-C.sub.6alkanoyl, C.sub.1-C.sub.6alkylsulfonyl,
C.sub.1-C.sub.6haloalkylsulfonyl, amino, mono- and
di-(C.sub.1-C.sub.6alkyl)amino.
49.-59. (canceled)
60. A pharmaceutical composition, comprising at least one compound or salt
according to claim 1 in combination with a physiologically acceptable
carrier or excipient.
61. A method for reducing calcium conductance of a cellular capsaicin
receptor, comprising contacting a cell expressing a capsaicin receptor
with at least one compound or salt according to claim 1, and thereby
reducing calcium conductance of the capsaicin receptor.
62.-70. (canceled)
71. A method for inhibiting binding of vanilloid ligand to a capsaicin
receptor in vitro, the method comprising contacting capsaicin receptor
with at least one compound or salt according to claim 1, in an amount
sufficient to detectably inhibit vanilloid ligand binding to capsaicin
receptor.
72. A method for inhibiting binding of vanilloid ligand to a capsaicin
receptor in a patient, the method comprising contacting cells expressing
capsaicin receptor with at least one compound or salt according to claim
1, in an amount sufficient to detectably inhibit vanilloid ligand binding
to cells expressing a cloned capsaicin receptor in vitro, and thereby
inhibiting binding of vanilloid ligand to the capsaicin receptor in the
patient.
73. (canceled)
74. A method for treating a condition responsive to capsaicin receptor
modulation in a patient, comprising administering to the patient a
capsaicin receptor modulatory amount of a compound or salt according to
claim 1, and thereby alleviating the condition in the patient.
75. (canceled)
76. (canceled)
77. A method for treating pain in a patient, comprising administering to a
patient suffering from pain a capsaicin receptor modulatory amount of at
least one compound or salt according to claim 1, and thereby alleviating
pain in the patient.
78.-80. (canceled)
81. A method according to claim 77, wherein the patient is suffering from
neuropathic pain.
82. A method according to claim 77, wherein the patient is afflicted with
a condition selected from: postmastectomy pain syndrome, stump pain,
phantom limb pain, oral neuropathic pain, toothache, postherpetic
neuralgia, diabetic neuropathy, reflex sympathetic dystrophy, trigeminal
neuralgia, osteoarthritis, rheumatoid arthritis, fibromyalgia,
Guillain-Barre syndrome, meralgia paresthetica, burning-mouth syndrome,
bilateral peripheral neuropathy, causalgia, neuritis, neuronitis,
neuralgia, AIDS-related neuropathy, MS-related neuropathy, spinal cord
injury-related pain, surgery-related pain, musculoskeletal pain, back
pain, headache, migraine, angina, labor, hemorrhoids, dyspepsia,
Charcot's pains, intestinal gas, menstruation, cancer, venom exposure,
irritable bowel syndrome, inflammatory bowel disease and trauma.
83. (canceled)
84. A method for treating a condition selected from the group consisting
of itch, cough, hiccup, urinary incontinence or overactive bladder in a
patient, comprising administering to a patient a capsaicin receptor
modulatory amount of a compound or salt according to claim 1, and thereby
alleviating the condition in the patient.
85. (canceled)
86. (canceled)
87. A method promoting weight loss in an obese patient, comprising
administering to a patient a capsaicin receptor modulatory amount of a
compound or salt according to claim 1, and thereby promoting weight loss
in the patient.
88.-91. (canceled)
92. A packaged pharmaceutical preparation, comprising:(a) a pharmaceutical
composition according to claim 60 in a container; and(b) instructions for
using the composition to treat pain.
93.-97. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001]This application is a continuation of U.S. patent application Ser.
No. 10/891,832, now allowed, filed Jul. 14, 2004, which claims the
benefit of U.S. Provisional Patent Application No. 60/486,948, filed Jul.
14, 2003. The contents of each of these applications are incorporated
herein in their entirety.
FIELD OF THE INVENTION
[0002]This invention relates generally to substituted quinolin-4-ylamine
analogues that have useful pharmacological properties. The invention
further relates to the use of such compounds for treating conditions
related to capsaicin receptor activation, for identifying other agents
that bind to capsaicin receptor, and as probes for the detection and
localization of capsaicin receptors.
BACKGROUND OF THE INVENTION
[0003]Pain perception, or nociception, is mediated by the peripheral
terminals of a group of specialized sensory neurons, termed
"nociceptors." A wide variety of physical and chemical stimuli induce
activation of such neurons in mammals, leading to recognition of a
potentially harmful stimulus. Inappropriate or excessive activation of
nociceptors, however, can result in debilitating acute or chronic pain.
[0004]Neuropathic pain involves pain signal transmission in the absence of
stimulus, and typically results from damage to the nervous system. In
most instances, such pain is thought to occur because of sensitization in
the peripheral and central nervous systems following initial damage to
the peripheral system (e.g., via direct injury or systemic disease).
Neuropathic pain is typically burning, shooting and unrelenting in its
intensity and can sometimes be more debilitating that the initial injury
or disease process that induced it.
[0005]Existing treatments for neuropathic pain are largely ineffective.
Opiates, such as morphine, are potent analgesics, but their usefulness is
limited because of adverse side effects, such as physical addictiveness
and withdrawal properties, as well as respiratory depression, mood
changes, and decreased intestinal motility with concomitant constipation,
nausea, vomiting, and alterations in the endocrine and autonomic nervous
systems. In addition, neuropathic pain is frequently non-responsive or
only partially responsive to conventional opioid analgesic regimens.
Treatments employing the N-methyl-D-aspartate antagonist ketamine or the
alpha(2)-adrenergic agonist clonidine can reduce acute or chronic pain,
and permit a reduction in opioid consumption, but these agents are often
poorly tolerated due to side effects.
[0006]Topical treatment with capsaicin has been used to treat chronic and
acute pain, including neuropathic pain. Capsaicin is a pungent substance
derived from the plants of the Solanaceae family (which includes
hot
chili peppers) and appears to act selectively on the small diameter
afferent nerve fibers (A-delta and C fibers) that are believed to mediate
pain. The response to capsaicin is characterized by persistent activation
of nociceptors in peripheral tissues, followed by eventual
desensitization of peripheral nociceptors to one or more stimuli. From
studies in animals, capsaicin appears to trigger C fiber membrane
depolarization by opening cation selective channels for calcium and
sodium.
[0007]Similar responses are also evoked by structural analogues of
capsaicin that share a common vanilloid moiety. One such analogue is
resiniferatoxin (RTX), a natural product of Euphorbia plants. The term
vanilloid receptor (VR) was coined to describe the neuronal membrane
recognition site for capsaicin and such related irritant compounds. The
capsaicin response is competitively inhibited (and thereby antagonized)
by another capsaicin analog, capsazepine, and is also inhibited by the
non-selective cation channel blocker ruthenium red. These antagonists
bind to VR with no more than moderate affinity (typically with K.sub.i
values of no lower than 140 .mu.M).
[0008]Rat and human vanilloid receptors have been cloned from dorsal root
ganglion cells. The first type of vanilloid receptor to be identified is
known as vanilloid receptor type 1 (VR1), and the terms "VR1" and
"capsaicin receptor" are used interchangeably herein to refer to rat
and/or human receptors of this type, as well as mammalian homologues. The
role of VR1 in pain sensation has been confirmed using mice lacking this
receptor, which exhibit no vanilloid-evoked pain behavior, and impaired
responses to heat and inflammation. VR1 is a nonselective cation channel
with a threshold for opening that is lowered in response to elevated
temperatures, low pH, and capsaicin receptor agonists. For example, the
channel usually opens at temperatures higher than about 45.degree. C.
Opening of the capsaicin receptor channel is generally followed by the
release of inflammatory peptides from neurons expressing the receptor and
other nearby neurons, increasing the pain response. After initial
activation by capsaicin, the capsaicin receptor undergoes a rapid
desensitization via phosphorylation by cAMP-dependent protein kinase.
[0009]Because of their ability to desensitize nociceptors in peripheral
tissues, VR1 agonist vanilloid compounds have been used as topical
anesthetics. However, agonist application may itself cause burning pain,
which limits this therapeutic use. Recently, it has been reported that
VR1 antagonists, including nonvanilloid compounds, are also useful for
the treatment of pain (see PCT International Application Publication
Number WO 02/08221, which published Jan. 31, 2002).
[0010]Thus, compounds that interact with VR1, but do not elicit the
initial painful sensation of VR1 agonist vanilloid compounds, are
desirable for the treatment of chronic and acute pain, including
neuropathic pain. Antagonists of this receptor are particularly desirable
for the treatment of pain, as well as conditions such as tear gas
exposure, itch and urinary tract conditions such as urinary incontinence
and overactive bladder. The present invention fulfills this need, and
provides further related advantages.
SUMMARY OF THE INVENTION
[0011]The present invention provides substituted quinolin-4-ylamine
analogues characterized by the formula:
##STR00001##
as well as pharmaceutically acceptable salts of such compounds. Within
Formula I: [0012]Y and Z are each independently N or CR.sub.1. In certain
embodiments, Y and Z are independently N or CH; in further embodiments,
at least one of Y and Z is N (i.e., Y is N, Z is N or both Y and Z are
N). R.sub.1 is independently selected at each occurrence from hydrogen,
halogen, cyano, amino, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4haloalkyl,
C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4haloalkoxy and mono- and
di-(C.sub.1-C.sub.4alkyl)amino. [0013]R.sub.2 is: (i) hydrogen, halogen
or cyano; [0014](ii) a group of the formula --R.sub.c-M-A-R.sub.y,
wherein: [0015]R.sub.c is C.sub.0-C.sub.3alkyl or is joined to R.sub.y
or R.sub.z, to form a 4- to 10-membered carbocycle or heterocycle that is
substituted with from 0 to 2 substituents independently chosen from
R.sub.b; [0016]M is a single covalent bond, O, S, SO.sub.2, C(.dbd.O),
OC(.dbd.O), C(.dbd.O)O, O--C(.dbd.O)O, C(.dbd.O)N(R.sub.z),
OC(.dbd.O)N(R.sub.z), N(R.sub.z)C(.dbd.O), N(R.sub.z)SO.sub.2,
SO.sub.2N(R.sub.z) or N(R.sub.z); [0017]A is a single covalent bond or
C.sub.1-C.sub.8alkyl substituted with from 0 to 3 substituents
independently chosen from R.sub.b; and [0018]R.sub.y and R.sub.z, if
present, are: [0019](a) independently hydrogen, C.sub.1-C.sub.8alkyl,
C.sub.2-C.sub.8alkyl ether, C.sub.2-C.sub.8alkenyl, a 4-to 10-membered
carbocycle or heterocycle, or joined to R.sub.c, to form a 4- to
10-membered carbocycle or heterocycle, wherein each non-hydrogen R.sub.y
and R.sub.z is substituted with from 0 to 6 substituents independently
chosen from R.sub.b; or [0020](b) joined to form a 4- to 10-membered
carbocycle or heterocycle that is substituted with from 0 to 6
substituents independently chosen from R.sub.b; or [0021](iii) taken
together with R.sub.7 to form a fused 5- to 7-membered ring that is
substituted with from 0 to 3 substituents independently chosen from oxo
and C.sub.1-C.sub.4alkyl.In certain embodiments, R.sub.2 is not
--NH.sub.2. [0022]R.sub.7 is hydrogen, COOH, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4alkoxycarbonyl or taken together
with R.sub.2 to form a fused, optionally substituted ring. [0023]Ar.sub.1
is phenyl or 6-membered heteroaryl, each of which is unsubstituted or
substituted ortho to the point of attachment with 1 or 2 substituents
independently chosen from groups of the formula LR.sub.a. [0024]Ar.sub.2
is 6- to 10-membered aryl or 5- to 10-membered heteroaryl, each of which
is substituted with from 0 to 6 substituents independently chosen from
oxo and groups of the formula LR.sub.a. Within certain compounds of
Formula I, Ar.sub.2 is a 5- to 10-membered aromatic heterocycle that is
optionally substituted as described above. Within further such compounds,
Ar.sub.2 of Formula I is phenyl or a 6-membered aromatic heterocycle,
optionally substituted as described above. [0025]L is independently
selected at each occurrence from a single covalent bond, O, C(.dbd.O),
OC(.dbd.O), C(.dbd.O)O, OC(.dbd.O)O, S(O).sub.m, N(R.sub.x),
C(.dbd.O)N(R.sub.x), N(R.sub.x)C(.dbd.O), N(R.sub.x)S(O).sub.m,
S(O).sub.mN(R.sub.x) and N[S(O).sub.mR.sub.w]S(O).sub.m; wherein m is
independently selected at each occurrence from 0, 1 and 2; R.sub.x is
independently selected at each occurrence from hydrogen,
C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkanoyl and
C.sub.1-C.sub.6alkylsulfonyl; and R.sub.w is hydrogen or
C.sub.1-C.sub.6alkyl. [0026]R.sub.a is independently selected at each
occurrence from: [0027](i) hydrogen, halogen, cyano and nitro; and
[0028](ii) C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl,
C.sub.2-C.sub.8alkynyl, C.sub.1-C.sub.8haloalkyl, C.sub.2-C.sub.8alkyl
ether, mono- and di-(C.sub.1-C.sub.8alkyl)amino and (3- to 10-membered
heterocycle)C.sub.0-C.sub.6alkyl, each of which is substituted with from
0 to 6 substituents independently selected from R.sub.b. [0029]R.sub.b
is independently chosen at each occurrence from hydroxy, halogen, amino,
aminocarbonyl, cyano, nitro, oxo, COOH, C.sub.1-C.sub.8alkyl,
C.sub.1-C.sub.8alkoxy, C.sub.1-C.sub.8alkylthio, C.sub.1-C.sub.8alkanoyl,
C.sub.1-C.sub.8alkanoyloxy, C.sub.1-C.sub.8alkoxycarbonyl,
C.sub.1-C.sub.8alkyl ether, C.sub.1-C.sub.8hydroxyalkyl,
C.sub.1-C.sub.8haloalkyl, phenylC.sub.0-C.sub.8alkyl, mono- and
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl,
C.sub.1-C.sub.8alkylsulfonyl and (4- to 7-membered
heterocycle)C.sub.0-C.sub.8alkyl.
[0030]Within certain aspects, compounds of Formula I are VR1 modulators
and exhibit a K.sub.i of no greater than 1 micromolar, 100 nanomolar, 50
nanomolar, 10 nanomolar or 1 nanomolar in a capsaicin receptor binding
assay and/or have an EC.sub.50 or IC.sub.50 value of no greater than 1
micromolar, 100 nanomolar, 50 nanomolar, 10 nanomolar or 1 nanomolar in
an assay for determination of capsaicin receptor agonist or antagonist
activity.
[0031]In certain embodiments, VR1 modulators as described herein are VR1
antagonists and exhibit no detectable agonist activity in an in vitro
assay of capsaicin receptor activation.
[0032]Within certain aspects, compounds as described herein are labeled
with a detectable marker (e.g., radiolabeled or fluorescein conjugated).
[0033]The present invention further provides, within other aspects,
pharmaceutical compositions comprising at least one compound as described
herein (i.e., a compound as provided herein or a pharmaceutically
acceptable salt thereof) in combination with a physiologically acceptable
carrier or excipient.
[0034]Within further aspects, methods are provided for reducing calcium
conductance of a cellular capsaicin receptor, comprising contacting a
cell (e.g., neuronal) expressing a capsaicin receptor with a capsaicin
receptor modulatory amount of at least one VR1 modulator as described
herein. Such contact may occur in vivo or in vitro.
[0035]Methods are further provided for inhibiting binding of vanilloid
ligand to a capsaicin receptor. Within certain such aspects, the
inhibition takes place in vitro. Such methods comprise contacting a
capsaicin receptor with at least one VR1 modulator as described herein,
under conditions and in an amount sufficient to detectably inhibit
vanilloid ligand binding to the capsaicin receptor. Within other such
aspects, the capsaicin receptor is in a patient. Such methods comprise
contacting cells expressing a capsaicin receptor in a patient with at
least one VR1 modulator as described herein in an amount sufficient to
detectably inhibit vanilloid ligand binding to cells expressing a cloned
capsaicin receptor in vitro, and thereby inhibiting binding of vanilloid
ligand to the capsaicin receptor in the patient.
[0036]The present invention further provides methods for treating a
condition responsive to capsaicin receptor modulation in a patient,
comprising administering to the patient a capsaicin receptor modulatory
amount of at least one VR1 modulator as described herein.
[0037]Within other aspects, methods are provided for treating pain in a
patient, comprising administering to a patient suffering from pain a
capsaicin receptor modulatory amount of at least one VR1 modulator as
described herein.
[0038]Methods are further provided for treating itch, urinary
incontinence, overactive bladder, cough and/or hiccup in a patient,
comprising administering to a patient suffering from one or more of the
foregoing conditions a capsaicin receptor modulatory amount of at least
one VR1 modulator as described herein.
[0039]The present invention further provides methods for promoting weight
loss in an obese patient, comprising administering to an obese patient a
capsaicin receptor modulatory amount of at least one VR1 modulator as
described herein.
[0040]Methods are further provided for identifying an agent that binds to
capsaicin receptor, comprising: (a) contacting capsaicin receptor with a
labeled VR1 modulator as described herein under conditions that permit
binding of the VR1 modulator to capsaicin receptor, thereby generating
bound, labeled VR1 modulator; (b) detecting a signal that corresponds to
the amount of bound, labeled VR1 modulator in the absence of test agent;
(c) contacting the bound, labeled VR1 modulator with a test agent; (d)
detecting a signal that corresponds to the amount of bound labeled VR1
modulator in the presence of test agent; and (e) detecting a decrease in
signal detected in step (d), as compared to the signal detected in step
(b), and therefrom identifying an agent that binds to capsaicin receptor.
[0041]Within further aspects, the present invention provides methods for
determining the presence or absence of capsaicin receptor in a sample,
comprising: (a) contacting a sample with a VR1 modulator as described
herein under conditions that permit binding of the VR1 modulator to
capsaicin receptor; and (b) detecting a level of the VR1 modulator bound
to capsaicin receptor.
[0042]The present invention also provides packaged pharmaceutical
preparations, comprising: (a) a pharmaceutical composition as described
herein in a container; and (b) instructions for using the composition to
treat one or more conditions responsive to capsaicin receptor modulation,
such as pain, itch, urinary incontinence, overactive bladder, cough,
hiccup and/or obesity.
[0043]In yet another aspect, the present invention provides methods of
preparing the compounds disclosed herein, including the intermediates.
[0044]These and other aspects of the invention will become apparent upon
reference to the following detailed description.
DETAILED DESCRIPTION
[0045]As noted above, the present invention provides substituted
quinolin-4-ylamine analogues. Such compounds may be used in vitro or in
vivo, to modulate (preferably inhibit) capsaicin receptor activity in a
variety of contexts.
Terminology
[0046]Compounds are generally described herein using standard
nomenclature. For compounds having asymmetric centers, it should be
understood that (unless otherwise specified) all of the optical isomers
and mixtures thereof are encompassed. In addition, compounds with
carbon-carbon double bonds may occur in Z- and E-forms, with all isomeric
forms of the compounds being included in the present invention unless
otherwise specified. Where a compound exists in various tautomeric forms,
a recited compound is not limited to any one specific tautomer, but
rather is intended to encompass all tautomeric forms. Certain compounds
are described herein using a general formula that includes variables
(e.g., R.sub.3, A.sub.1, X). Unless otherwise specified, each variable
within such a formula is defined independently of any other variable, and
any variable that occurs more than one time in a formula is defined
independently at each occurrence.
[0047]The term "quinolin-4-ylamine analogue," as used herein, encompasses
all compounds of Formula I as well as pharmaceutically acceptable salts
of such compounds. Such compounds include analogues in which the
quinoline core is modified by the addition of ring nitrogen atoms, as
well as analogues in which varied substituents, as described in more
detail below, are attached to such a core structure. In other words,
compounds that are quinolin-4-ylamines, [1,8]naphthyridin-4-ylamines,
[1,5]naphthyridin-4-ylamines and pyrido[2,3-b]pyrazin-8-ylamines are
within the scope of quinolin-4-ylamine analogues.
[0048]A "pharmaceutically acceptable salt" of a compound recited herein is
an acid or base salt that is generally considered in the art to be
suitable for use in contact with the tissues of human beings or animals
without excessive toxicity, irritation, allergic response, or other
problem or complication. Such salts include mineral and organic acid
salts of basic residues such as amines, as well as alkali or organic
salts of acidic residues such as carboxylic acids. Specific
pharmaceutical salts include, but are not limited to, salts of acids such
as hydrochloric, phosphoric, hydrobromic, malic, glycolic, fumaric,
sulfuric, sulfamic, sulfanilic, formic, toluenesulfonic, methanesulfonic,
benzene sulfonic, ethane disulfonic, 2-hydroxyethylsulfonic, nitric,
benzoic, 2-acetoxybenzoic, citric, tartaric, lactic, stearic, salicylic,
glutamic, ascorbic, pamoic, succinic, fumaric, maleic, propionic,
hydroxymaleic, hydroiodic, phenylacetic, alkanoic such as acetic,
HOOC--(CH.sub.2).sub.n--COOH where n is 0-4, and the like. Similarly,
pharmaceutically acceptable cations include, but are not limited to
sodium, potassium, calcium, aluminum, lithium and ammonium. Those of
ordinary skill in the art will recognize further pharmaceutically
acceptable salts for the compounds provided herein, including those
listed by Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing
Company, Easton, Pa., p. 1418 (1985). In general, a pharmaceutically
acceptable acid or base salt can be synthesized from a parent compound
that contains a basic or acidic moiety by any conventional chemical
method. Briefly, such salts can be prepared by reacting the free acid or
base forms of these compounds with a stoichiometric amount of the
appropriate base or acid in water or in an organic solvent, or in a
mixture of the two; generally, the use of nonaqueous media, such as
ether, ethyl acetate, ethanol, isopropanol or acetonitrile, is preferred.
[0049]It will be apparent that each compound of Formula I may, but need
not, be formulated as a hydrate, solvate or non-covalent complex. In
addition, the various crystal forms and polymorphs are within the scope
of the present invention. Also provided herein are prodrugs of the
compounds of Formula I. A "prodrug" is a compound that may not fully
satisfy the structural requirements of the compounds provided herein, but
is modified in vivo, following administration to a patient, to produce a
compound of Formula I, or other formula provided herein. For example, a
prodrug may be an acylated derivative of a compound as provided herein.
Prodrugs include compounds wherein hydroxy, amine or sulfhydryl groups
are bonded to any group that, when administered to a mammalian subject,
cleaves to form a free hydroxy, amino, or sulfhydryl group, respectively.
Examples of prodrugs include, but are not limited to, acetate, formate
and benzoate derivatives of alcohol and amine functional groups within
the compounds provided herein. Prodrugs of the compounds provided herein
may be prepared by modifying functional groups present in the compounds
in such a way that the modifications are cleaved to the parent compounds.
[0050]As used herein, the term "alkyl" refers to a straight or branched
chain or cyclic saturated aliphatic hydrocarbon. Alkyl groups include
groups having from 1 to 8 carbon atoms (C.sub.1-C.sub.8alkyl), from 1 to
6 carbon atoms (C.sub.1-C.sub.6alkyl) and from 1 to 4 carbon atoms
(C.sub.1-C.sub.4alkyl), such as methyl, ethyl, propyl, isopropyl,
n-butyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, isopentyl, neopentyl,
hexyl, 2-hexyl, 3-hexyl, 3-methylpentyl, cyclopropyl, cyclopropylmethyl,
cyclopentyl, cyclopentylmethyl, cyclohexyl, cycloheptyl and norbornyl.
"C.sub.0-C.sub.4alkyl" refers to a single covalent bond (C.sub.0) or an
alkyl group having 1, 2, 3 or 4 carbon atoms; "C.sub.0-C.sub.6alkyl"
refers to a single covalent bond or a C.sub.1-C.sub.6alkyl group;
"C.sub.0-C.sub.8alkyl" refers to a single covalent bond or a
C.sub.1-C.sub.8alkyl group. In certain embodiments, preferred alkyl
groups are straight or branched chain. In some instances herein, a
substituent of an alkyl group is specifically indicated. For example,
"C.sub.1-C.sub.6Cyanoalkyl" refers to a C.sub.1-C.sub.6alkyl group that
has at least one CN substituent. One representative branched cyanoalkyl
group is --C(CH.sub.3).sub.2CN. Similarly, "C.sub.1-C.sub.6hydroxyalkyl"
refers to a C.sub.1-C.sub.6alkyl group that has at least one --OH
substituent.
[0051]Similarly, "alkenyl" refers to straight or branched chain or cyclic
alkene groups, in which at least one unsaturated carbon-carbon double
bond is present. Alkenyl groups include C.sub.2-C.sub.8alkenyl,
C.sub.2-C.sub.6alkenyl and C.sub.2-C.sub.4alkenyl groups, which have from
2 to 8, 2 to 6 or 2 to 4 carbon atoms, respectively, such as ethenyl,
allyl or isopropenyl. "Alkynyl" refers to straight or branched chain or
cyclic alkyne groups, which have one or more unsaturated carbon-carbon
bonds, at least one of which is a triple bond. Alkynyl groups include
C.sub.2-C.sub.8alkynyl, C.sub.2-C.sub.6alkynyl and C.sub.2-C.sub.4alkynyl
groups, which have from 2 to 8, 2 to 6 or 2 to 4 carbon atoms,
respectively. In certain embodiments, preferred alkenyl and alkynyl
groups are straight or branched chain.
[0052]By "alkoxy," as used herein, is meant an alkyl group as described
above attached via an oxygen bridge. Alkoxy groups include
C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.4alkoxy groups, which have from 1
to 6 or 1 to 4 carbon atoms, respectively. Methoxy, ethoxy, propoxy,
isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, 2-pentoxy,
3-pentoxy, isopentoxy, neopentoxy, hexoxy, 2-hexoxy, 3-hexoxy, and
3-methylpentoxy are specific alkoxy groups.
[0053]Similarly, "alkylthio" refers to an alkyl, alkenyl or alkynyl group
as described above attached via a sulfur bridge. Preferred alkoxy and
alkylthio groups are those in which an alkyl group is attached via the
heteroatom bridge.
[0054]The term "oxo," as used herein, refers to a keto (C.dbd.O) group. An
oxo group that is a substituent of a nonaromatic carbon atom results in a
conversion of --CH.sub.2-- to --C(.dbd.O)--.
[0055]The term "alkanoyl" refers to an acyl group in a linear or branched
arrangement (e.g., --(C.dbd.O)-alkyl), where attachment is through the
carbon of the keto group. Alkanoyl groups include
C.sub.2-C.sub.8alkanoyl, C.sub.2-C.sub.6alkanoyl and
C.sub.2-C.sub.4alkanoyl groups, which have from 2 to 8, 2 to 6 or 2 to 4
carbon atoms, respectively. "C.sub.1alkanoyl" refers to --(C.dbd.O)--H,
which (along with C.sub.2-C.sub.8alkanoyl) is encompassed by the term
"C.sub.1-C.sub.8alkanoyl." Ethanoyl is C.sub.2alkanoyl.
[0056]An "alkanone" is a ketone group in which carbon atoms are in a
linear or branched alkyl arrangement. "C.sub.3-C.sub.8alkanone,"
"C.sub.3-C.sub.6alkanone" and "C.sub.3-C.sub.4alkanone" refer to an
alkanone having from 3 to 8, 6 or 4 carbon atoms, respectively. By way of
example, a C.sub.3 alkanone group has the structure
--CH.sub.2--(C.dbd.O)--CH.sub.3.
[0057]Similarly, "alkyl ether" refers to a linear or branched ether
substituent. Alkyl ether groups include C.sub.2-C.sub.8alkyl ether,
C.sub.2-C.sub.6alkyl ether and C.sub.2-C.sub.4alkyl ether groups, which
have 2 to 8, 6 or 4 carbon atoms, respectively. By way of example, a
C.sub.2 alkyl ether group has the structure --CH.sub.2--O--CH.sub.3.
[0058]The term "alkoxycarbonyl" refers to an alkoxy group linked via a
carbonyl (i.e., a group having the general structure
--C(.dbd.O)--O-alkyl). Alkoxycarbonyl groups include C.sub.2-C.sub.8,
C.sub.2-C.sub.6 and C.sub.2-C.sub.4alkoxycarbonyl groups, which have from
2 to 8, 6 or 4 carbon atoms, respectively. "C.sub.1alkoxycarbonyl" refers
to --C(.dbd.O)--OH, which is encompassed by the term
"C.sub.1-C.sub.8alkoxycarbonyl." "Methoxycarbonyl" refers to
C(.dbd.O)--OCH.sub.3.
[0059]"Alkanoyloxy," as used herein, refers to an alkanoyl group linked
via an oxygen bridge (i.e., a group having the general structure
--O--C(.dbd.O)-alkyl). Alkanoyloxy groups include C.sub.2-C.sub.8,
C.sub.2-C.sub.6 and C.sub.2-C.sub.4alkanoyloxy groups, which have from 2
to 8, 6 or 4 carbon atoms, respectively.
[0060]"Alkylsulfonyl" refers to groups of the formula --(SO.sub.2)-alkyl,
in which the sulfur atom is the point of attachment. Alkylsulfonyl groups
include C.sub.1-C.sub.6alkylsulfonyl and C.sub.1-C.sub.4alkylsulfonyl
groups, which have from 1 to 6 or 1 to 4 carbon atoms, respectively.
Methylsulfonyl is one representative alkylsulfonyl group.
[0061]"Alkylamino" refers to a secondary or tertiary amine having the
general structure --NH-alkyl or --N(alkyl)(alkyl), wherein each alkyl may
be the same or different. Such groups include, for example, mono- and
di-(C.sub.1-C.sub.8alkyl)amino groups, in which each alkyl may be the
same or different and may contain from 1 to 8 carbon atoms, as well as
mono- and di-(C.sub.1-C.sub.6alkyl)amino groups and mono- and
di-(C.sub.1-C.sub.4alkyl)amino groups.
[0062]"Alkylaminoalkyl" refers to an alkylamino group linked via an alkyl
group (i.e., a group having the general structure -alkyl-NH-alkyl or
-alkyl-N(alkyl)(alkyl)) in which each alkyl is selected independently.
Such groups include, for example, mono- and
di-(C.sub.1-C.sub.8alkyl)aminoC.sub.1-C.sub.8alkyl, mono- and
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.1-C.sub.6alkyl and mono- and
di-(C.sub.1-C.sub.4alkyl)aminoC.sub.1-C.sub.4alkyl, in which each alkyl
may be the same or different. "Mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.6alkyl" refers to a mono- or
di-(C.sub.1-C.sub.6alkyl)amino group linked via a direct bond or a
C.sub.1-C.sub.6alkyl group. The following are representative
alkylaminoalkyl groups:
##STR00002##
[0063]The term "aminocarbonyl" refers to an amide group (i.e.,
--(C.dbd.O)NH.sub.2). "Mono- or di-(C.sub.1-C.sub.8alkyl)aminocarbonyl"
is an aminocarbonyl group in which one or both of the hydrogen atoms is
replaced with C.sub.1-C.sub.8alkyl. If both hydrogen atoms are so
replaced, the C.sub.1-C.sub.8alkyl groups may be the same or different.
[0064]The term "halogen" refers to fluorine, chlorine, bromine or iodine.
[0065]A "haloalkyl" is a branched, straight-chain or cyclic alkyl group,
substituted with 1 or more halogen atoms (e.g.,
"C.sub.1-C.sub.8haloalkyl" groups have from 1 to 8 carbon atoms;
"C.sub.1-C.sub.6haloalkyl" groups have from 1 to 6 carbon atoms).
Examples of haloalkyl groups include, but are not limited to, mono-, di-
or tri-fluoromethyl; mono-, di- or tri-chloromethyl; mono-, di-, tri-,
tetra- or penta-fluoroethyl; mono-, di-, tri-, tetra- or
penta-chloroethyl; and 1,2,2,2-tetrafluoro-1-trifluoromethyl-ethyl.
Typical haloalkyl groups are trifluoromethyl and difluoromethyl. The term
"haloalkoxy" refers to a haloalkyl group as defined above attached via an
oxygen bridge. "C.sub.1-C.sub.8haloalkoxy" groups have from 1 to 8 carbon
atoms. "Haloalkylsulfonyl" refers to a haloalkyl group attached via a
--SO.sub.2-- bridge. "C.sub.1-C.sub.6haloalkylsulfonyl" groups have from
1 to 6 carbon atoms.
[0066]A dash ("-") that is not between two letters or symbols is used to
indicate a point of attachment for a substituent. For example,
--CONH.sub.2 is attached through the carbon atom.
[0067]A "heteroatom," as used herein, is oxygen, sulfur or nitrogen.
[0068]A "carbocycle" or "carbocyclic group" comprises at least one ring
formed entirely by carbon-carbon bonds (referred to herein as a
carbocyclic ring), and does not contain a heterocyclic ring. Unless
otherwise specified, each carbocyclic ring within a carbocycle may be
saturated, partially saturated or aromatic. A carbocycle generally has
from 1 to 3 fused, pendant or spiro rings; carbocycles within certain
embodiments have one ring or two fused rings. Typically, each ring
contains from 3 to 8 ring members (i.e., C.sub.3-C.sub.8);
C.sub.5-C.sub.7 rings are recited in certain embodiments. Carbocycles
comprising fused, pendant or spiro rings typically contain from 9 to 14
ring members. Certain representative carbocycles are cycloalkyl (i.e.,
groups that comprise saturated and/or partially saturated rings, such as
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,
cyclooctyl, adamantyl, decahydro-naphthalenyl, octahydro-indenyl, and
partially saturated variants of any of the foregoing, such as
cyclohexenyl). Other carbocycles are aryl (i.e., contain at least one
aromatic carbocyclic ring, with or without additional fused, pendant or
spiro cyclolkyl rings). Such carbocycles include, for example, phenyl,
naphthyl, fluorenyl, indanyl and 1,2,3,4-tetrahydro-naphthyl.
[0069]Certain carbocycles recited herein are
C.sub.6-C.sub.10arylC.sub.0-C.sub.8alkyl groups (i.e., groups in which a
carbocyclic group comprising at least one aromatic ring is linked via a
direct bond or a C.sub.1-C.sub.8alkyl group). Such groups include, for
example, phenyl and indanyl, as well as groups in which either of the
foregoing is linked via C.sub.1-C.sub.8alkyl, preferably via
C.sub.1-C.sub.4alkyl. Phenyl groups linked via a direct bond or alkyl
group may be designated phenylC.sub.0-C.sub.8alkyl (e.g., benzyl,
1-phenyl-ethyl, 1-phenyl-propyl and 2-phenyl-ethyl). A
phenylC.sub.0-C.sub.8alkoxy group is a phenyl ring linked via an oxygen
bridge or an alkoxy group having from 1 to 8 carbon atoms (e.g., phenoxy
or benzoxy).
[0070]A "heterocycle" or "heterocyclic group" has from 1 to 3 fused,
pendant or spiro rings, at least one of which is a heterocyclic ring
(i.e., one or more ring atoms is a heteroatom, with the remaining ring
atoms being carbon). Typically, a heterocyclic ring comprises 1, 2, 3 or
4 heteroatoms; within certain embodiments each heterocyclic ring has 1 or
2 heteroatoms per ring. Each heterocyclic ring generally contains from 3
to 8 ring members (rings having from 4 or 5 to 7 ring members are recited
in certain embodiments) and heterocycles comprising fused, pendant or
spiro rings typically contain from 9 to 14 ring members. Certain
heterocycles comprise a sulfur atom as a ring member; in certain
embodiments, the sulfur atom is oxidized to SO or SO.sub.2. Heterocycles
may be optionally substituted with a variety of substituents, as
indicated. Unless otherwise specified, a heterocycle may be a
heterocycloalkyl group (i.e., each ring is saturated or partially
saturated) or a heteroaryl group (i.e., at least one ring within the
group is aromatic). A heterocyclic group may generally be linked via any
ring or substituent atom, provided that a stable compound results.
N-linked heterocyclic groups are linked via a component nitrogen atom.
[0071]Heterocyclic groups include, for example, azepanyl, azocinyl,
benzimidazolyl, benzimidazolinyl, benzisothiazolyl, benzisoxazolyl,
benzofuranyl, benzothiofuranyl, benzoxazolyl, benzothiazolyl,
benztetrazolyl, chromanyl, chromenyl, cinnolinyl, decahydroquinolinyl,
dihydrofuro[2,3-b]tetrahydrofuranyl, dihydroisoquinolinyl,
dihydrotetrahydrofuranyl, 1,4-dioxa-8-aza-spiro[4.5]decyl, dithiazinyl,
furanyl, furazanyl, imidazolinyl, imidazolidinyl, imidazolyl, indazolyl,
indolenyl, indolinyl, indolizinyl, indolyl, isobenzofuranyl,
isochromanyl, isoindazolyl, isoindolinyl, isoindolyl, isothiazolyl,
isoxazolyl, isoquinolinyl, morpholinyl, naphthyridinyl,
octahydroisoquinolinyl, oxadiazolyl, oxazolidinyl, oxazolyl,
phthalazinyl, piperazinyl, piperidinyl, piperidinyl, piperidonyl,
pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl,
pyrazolyl, pyridazinyl, pyridoimidazolyl, pyridooxazolyl,
pyridothiazolyl, pyridyl, pyrimidyl, pyrrolidinyl, pyrrolidonyl,
pyrrolinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl,
quinuclidinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, tetrazolyl,
thiadiazinyl, thiadiazolyl, thiazolyl, thienothiazolyl, thienooxazolyl,
thienoimidazolyl, thienyl, thiophenyl, thiomorpholinyl and variants
thereof in which the sulfur atom is oxidized, triazinyl, and any of the
foregoing that are substituted with from 1 to 4 substituents as described
above.
[0072]Certain heterocyclic groups are 4- to 10-membered, 5- to
10-membered, 3- to 7-membered, 4- to 7-membered or 5- to 7-membered
groups that contain 1 heterocyclic ring or 2 fused or spiro rings,
optionally substituted. 4- to 10-membered heterocycloalkyl groups
include, for example, piperidinyl, piperazinyl, pyrrolidinyl, azepanyl,
1,4-dioxa-8-aza-spiro[4.5]dec-8-yl, morpholino, thiomorpholino and
1,1-dioxo-thiomorpholin-4-yl. Such groups may be substituted as
indicated. Representative aromatic heterocycles are azocinyl, pyridyl,
pyrimidyl, imidazolyl, tetrazolyl and 3,4-dihydro-1H-isoquinolin-2-yl.
(C.sub.3-C.sub.10)heterocycloalkyls include, for example, piperidinyl,
piperazinyl, pyrrolidinyl, azepanyl, 1,4-dioxa-8-aza-spiro[4.5]dec-8-yl,
morpholino, thiomorpholino, and 1,1-dioxo-thiomorpholin-4-yl, as well as
groups in which each of the foregoing is substituted. Representative
aromatic heterocycles are azocinyl, pyridyl, pyrimidyl, imidazolyl,
tetrazolyl and 3,4-dihydro-1H-isoquinolin-2-yl.
[0073]Additional heterocyclic groups include, for example, acridinyl,
azepanyl, azocinyl, benzimidazolyl, benzimidazolinyl, benzisothiazolyl,
benzisoxazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl,
benzoxazolyl, benzothiazolyl, benzotriazolylcarbazolyl, benztetrazolyl,
NH-carbazolyl, carbolinyl, chromanyl, chromenyl, cinnolinyl,
decahydroquinolinyl, dihydrofuro[2,3-b]tetrahydrofuran,
dihydroisoquinolinyl, dihydrotetrahydrofuranyl,
1,4-dioxa-8-aza-spiro[4.5]dec-8-yl, dithiazinyl, furanyl, furazanyl,
imidazolinyl, imidazolidinyl, imidazolyl, indazolyl, indolenyl,
indolinyl, indolizinyl, indolyl, isobenzofuranyl, isochromanyl,
isoindazolyl, isoindolinyl, isoindolyl, isothiazolyl, isoxazolyl,
isoquinolinyl, morpholinyl, naphthyridinyl, octahydroisoquinolinyl,
oxadiazolyl, oxazolidinyl, oxazolyl, phenanthridinyl, phenanthrolinyl,
phenazinyl, phenothiazinyl, phenoxathiinyl, phenoxazinyl, phthalazinyl,
piperazinyl, piperidinyl, piperidinyl, piperidonyl, pteridinyl, purinyl,
pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl,
pyridoimidazolyl, pyridooxazolyl, pyridothiazolyl, pyridyl, pyrimidyl,
pyrrolidinyl, pyrrolidonyl, pyrrolinyl, pyrrolyl, quinazolinyl,
quinolinyl, quinoxalinyl, quinuclidinyl, tetrahydroisoquinolinyl,
tetrahydroquinolinyl, tetrazolyl, thiadiazinyl, thiadiazolyl,
thianthrenyl, thiazolyl, thienothiazolyl, thienooxazolyl,
thienoimidazolyl, thienyl, thiophenyl, thiomorpholinyl and variants
thereof in which the sulfur atom is oxidized, triazinyl, xanthenyl and
any of the foregoing that are substituted with from 1 to 4 substituents
as described above.
[0074]A "heterocycleC.sub.0-C.sub.8alkyl" is a heterocyclic group linked
via a single covalent bond or C.sub.1-C.sub.8alkyl group. A (3- to
10-membered heterocycle)C.sub.0-C.sub.6alkyl is a heterocyclic group
having from 3 to 10 ring members linked via a direct bond or a
C.sub.1-C.sub.6alkyl group. A (5- to 7-membered
heterocycle)C.sub.0-C.sub.8alkyl is a 5- to 7-membered heterocyclic ring
linked via a single covalent bond or a C.sub.1-C.sub.8alkyl group; a (4-
to 7-membered heterocycloalkyl)C.sub.0-C.sub.4alkyl is a 4-to 7-membered
heterocycloalkyl ring linked via a single covalent bond or a
C.sub.1-C.sub.4alkyl group. I
[0075]A "substituent," as used herein, refers to a molecular moiety that
is covalently bonded to an atom within a molecule of interest. For
example, a "ring substituent" may be a moiety such as a halogen, alkyl
group, haloalkyl group or other group discussed herein that is covalently
bonded to an atom (preferably a carbon or nitrogen atom) that is a ring
member. The term "substitution" refers to replacing a hydrogen atom in a
molecular structure with a substituent as described above, such that the
valence on the designated atom is not exceeded, and such that a
chemically stable compound (i.e., a compound that can be isolated,
characterized, and tested for biological activity) results from the
substitution.
[0076]Groups that are "optionally substituted" are unsubstituted or are
substituted by other than hydrogen at one or more available positions,
typically 1, 2, 3, 4 or 5 positions, by one or more suitable groups
(which may be the same or different). Such optional substituents include,
for example, hydroxy, halogen, cyano, nitro, C.sub.1-C.sub.8alkyl,
C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl, C.sub.1-C.sub.8alkoxy,
C.sub.2-C.sub.8alkyl ether, C.sub.3-C.sub.8alkanone,
C.sub.1-C.sub.8alkylthio, amino, mono- or di-(C.sub.1-C.sub.8alkyl)amino,
C.sub.1-C.sub.8haloalkyl, C.sub.1-C.sub.8haloalkoxy,
C.sub.1-C.sub.8alkanoyl, C.sub.2-C.sub.8alkanoyloxy,
C.sub.1-C.sub.8alkoxycarbonyl,
--COOH, --CONH.sub.2, mono- or di-(C.sub.1-C.sub.8alkyl)aminocarbonyl,
--SO.sub.2NH.sub.2, and/or mono or di(C.sub.1-C.sub.8alkyl)sulfonamido,
as well as carbocyclic and heterocyclic groups. Optional substitution is
also indicated by the phrase "substituted with from 0 to X substituents,"
where X is the maximum number of possible substituents. Certain
optionally substituted groups are substituted with from 0 to 2, 3 or 4
independently selected substituents (i.e., are unsubstituted or
substituted with up to the recited maximum number of substitutents).
[0077]The terms "VR1" and "capsaicin receptor" are used interchangeably
herein to refer to a type 1 vanilloid receptor. Unless otherwise
specified, these terms encompass both rat and human VR1 receptors (e.g.,
GenBank Accession Numbers AF327067, AJ277028 and NM.sub.--018727;
sequences of certain human VR1 cDNAs are provided in SEQ ID NOs:1-3, and
the encoded amino acid sequences shown in SEQ ID NOs:4 and 5, of U.S.
Pat. No. 6,482,611), as well as homologues thereof found in other
species.
[0078]A "VR1 modulator," also referred to herein as a "modulator," is a
compound that modulates VR1 activation and/or VR1-mediated signal
transduction. VR1 modulators specifically provided herein are compounds
of Formula I and pharmaceutically acceptable salts of compounds of
Formula I. A VR1 modulator may be a VR1 agonist or antagonist. A
modulator binds with "high affinity" if the K.sub.i at VR1 is less than 1
micromolar, preferably less than 100 nanomolar, 10 nanomolar or 1
nanomolar. A representative assay for determining K.sub.i at VR1 is
provided in Example 5, herein.
[0079]A modulator is considered an "antagonist" if it detectably inhibits
vanilloid ligand binding to VR1 and/or VR1-mediated signal transduction
(using, for example, the representative assay provided in Example 6); in
general, such an antagonist inhibits VR1 activation with a IC.sub.50
value of less than 1 micromolar, preferably less than 100 nanomolar, and
more preferably less than 10 nanomolar or 1 nanomolar within the assay
provided in Example 6. VR1 antagonists include neutral antagonists and
inverse agonists. In certain embodiments, capsaicin receptor antagonists
provided herein are not vanilloids.
[0080]An "inverse agonist" of VR1 is a compound that reduces the activity
of VR1 below its basal activity level in the absence of added vanilloid
ligand. Inverse agonists of VR1 may also inhibit the activity of
vanilloid ligand at VR1, and/or may also inhibit binding of vanilloid
ligand to VR1. The ability of a compound to inhibit the binding of
vanilloid ligand to VR1 may be measured by a binding assay, such as the
binding assay given in Example 5. The basal activity of VR1, as well as
the reduction in VR1 activity due to the presence of VR1 antagonist, may
be determined from a calcium mobilization assay, such as the assay of
Example 6.
[0081]A "neutral antagonist" of VR1 is a compound that inhibits the
activity of vanilloid ligand at VR1, but does not significantly change
the basal activity of the receptor (i.e., within a calcium mobilization
assay as described in Example 6 performed in the absence of vanilloid
ligand, VR1 activity is reduced by no more than 10%, more preferably by
no more than 5%, and even more preferably by no more than 2%; most
preferably, there is no detectable reduction in activity). Neutral
antagonists of VR1 may inhibit the binding of vanilloid ligand to VR1.
[0082]As used herein a "capsaicin receptor agonist" or "VR1 agonist" is a
compound that elevates the activity of the receptor above the basal
activity level of the receptor (i.e., enhances VR1 activation and/or
VR1-mediated signal transduction). Capsaicin receptor agonist activity
may be identified using the representative assay provided in Example 6.
In general, such an agonist has an EC.sub.50 value of less than 1
micromolar, preferably less than 100 nanomolar, and more preferably less
than 10 nanomolar within the assay provided in Example 6. In certain
embodiments, capsaicin receptor agonists provided herein are not
vanilloids.
[0083]A "vanilloid" is capsaicin or any capsaicin analogue that comprises
a phenyl ring with two oxygen atoms bound to adjacent ring carbon atoms
(one of which carbon atom is located para to the point of attachment of a
third moiety that is bound to the phenyl ring). A vanilloid is a
"vanilloid ligand" if it binds to VR1 with a K.sub.i (determined as
described herein) that is no greater than 10 .mu.M. Vanilloid ligand
agonists include capsaicin, olvanil, N-arachidonoyl-dopamine and
resiniferatoxin (RTX). Vanilloid ligand antagonists include capsazepine
and iodo-resiniferatoxin.
[0084]A "capsaicin receptor modulatory amount" is an amount that, upon
administration to a patient, achieves a concentration of VR1 modulator at
a capsaicin receptor within the patient that is sufficient to alter the
binding of vanilloid ligand to VR1 in vitro (using the assay provided in
Example 5) and/or VR1-mediated signal transduction (using an assay
provided in Example 6). The capsaicin receptor may be present, or
example, in a body fluid such as blood, plasma, serum, CSF, synovial
fluid, lymph, cellular interstitial fluid, tears or urine.
[0085]A "therapeutically effective amount" is an amount that, upon
administration, is sufficient to provide detectable patient relief from a
condition being treated. Such relief may be detected using any
appropriate criteria, including alleviation of one or more symptoms such
as pain.
[0086]A "patient" is any individual treated with a compound (e.g., a VR1
modulator) as provided herein. Patients include humans, as well as other
animals such as companion animals (e.g., dogs and cats) and livestock.
Patients may be experiencing one or more symptoms of a condition
responsive to capsaicin receptor modulation (e.g., pain, exposure to
vanilloid ligand, itch, urinary incontinence, overactive bladder,
respiratory disorders, cough and/or hiccup), or may be free of such
symptom(s) (i.e., treatment may be prophylactic).
Substituted Quinolin-4-Ylamine Analogues
[0087]As noted above, the present invention provides substituted
quinolin-4-ylamine analogues that may be used in a variety of contexts,
including in the treatment of pain (e.g., neuropathic or peripheral
nerve-mediated pain); exposure to capsaicin; exposure to acid, heat,
light, tear gas air pollutants, pepper spray or related agents;
respiratory conditions such as asthma or chronic obstructive pulmonary
disease; itch; urinary incontinence or overactive bladder; cough or
hiccup; and/or obesity. Such compounds may also be used within in vitro
assays (e.g., assays for receptor activity), as probes for detection and
localization of VR1 and as standards in ligand binding and VR1-mediated
signal transduction assays.
[0088]Certain compounds provided herein detectably modulate the binding of
capsaicin to VR1 at nanomolar (i.e., submicromolar) concentrations,
preferably at subnanomolar concentrations, more preferably at
concentrations below 100 picomolar, 20 picomolar, 10 picomolar or 5
picomolar. Such modulators are preferably not vanilloids. Certain
preferred modulators are VR1 antagonists and have no detectable agonist
activity in the assay described in Example 6. Preferred VR1 modulators
further bind with high affinity to VR1, and do not substantially inhibit
activity of human EGF receptor tyrosine kinase.
[0089]Certain compounds further satisfy Formula II:
##STR00003##
or are a pharmaceutically acceptable salt of such a compound, wherein:
[0090]At least one of Y and Z is N; and the other of Y and Z is N or
CR.sub.1. In certain embodiments, Z is N (e.g., Z is N and Y is CH, or
both Y and Z are N). In further embodiments, Y is N. R.sub.1 is hydrogen,
halogen, cyano, amino, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4haloalkyl,
C.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4haloalkoxy or mono- or
di-(C.sub.1-C.sub.4alkyl)amino; in certain embodiments, R.sub.1 is
hydrogen, C.sub.1-C.sub.4alkyl or halo C.sub.1-C.sub.4alkyl, with
hydrogen preferred. [0091]R.sub.2 is: (i) hydrogen, halogen or cyano;
[0092](ii) a group of the formula --R.sub.c-M-A-R.sub.y, wherein:
[0093]R.sub.c is C.sub.0-C.sub.3alkyl or is joined to R.sub.y or R.sub.z,
to form a 4- to 10-membered carbocycle or heterocycle that is substituted
with from 0 to 2 substituents independently chosen from R.sub.b; [0094]M
is a single covalent bond, O, S, SO.sub.2,
##STR00004##
[0095]A is a single covalent bond or C.sub.1-C.sub.8alkyl substituted with
from 0 to 3 substituents independently chosen from R.sub.b; and
[0096]R.sub.y and R.sub.z, if present, are: [0097](a) independently
hydrogen, C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkyl ether,
C.sub.2-C.sub.8alkenyl, a 4-to 10-membered carbocycle or heterocycle, or
joined to R.sub.c to form a 4- to 10-membered carbocycle or heterocycle,
wherein each non-hydrogen R.sub.y and R.sub.z is substituted with from 0
to 6 substituents independently chosen from R.sub.b; or [0098](b) joined
to form a 4- to 10-membered carbocycle or heterocycle that is substituted
with from 0 to 6 substituents independently chosen from R.sub.b;
[0099]such that R.sub.2 is not --NH.sub.2; or [0100](iii) taken
together with R.sub.7 to form a fused 5- to 7-membered ring that is
substituted with from 0 to 3 substituents independently chosen from oxo
and C.sub.1-C.sub.4alkyl.
[0101]It will be apparent that, within groups of the formula
R.sub.c-M-A-R.sub.y, if two adjacent variables are bonds, then the two
variables are taken together to form a single bond. For example, if
R.sub.c is C.sub.0alkyl and M and A are both single covalent bonds, then
R.sub.2 is --R.sub.y. [0102]In certain compounds, R.sub.2 is: (i)
hydrogen, hydroxy or halogen; or (ii) C.sub.1-C.sub.6alkyl,
(C.sub.3-C.sub.7cycloalkyl)C.sub.0-C.sub.4alkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.1-C.sub.6hydroxyalkyl,
C.sub.2-C.sub.6alkyl ether, mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl or (4- to 7-membered
heterocycloalkyl)C.sub.0-C.sub.4alkyl, each of which is substituted with
from 0 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.6haloalkyl.
Representative R.sub.2 groups include hydrogen, C.sub.1-C.sub.6alkyl,
C.sub.2-C.sub.6alkyl ether, mono- or di-(C.sub.1-C.sub.6alkyl)amino,
morpholinylC.sub.0-C.sub.2alkyl, piperazinylC.sub.0-C.sub.2alkyl,
piperidinylC.sub.0-C.sub.2alkyl, phenylC.sub.0-C.sub.2alkyl and
pyridylC.sub.0-C.sub.2alkyl, each of which is substituted with from 0 to
4 substituents independently chosen from halogen, cyano, hydroxy, amino,
oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino, C.sub.1-C.sub.6alkyl and
C.sub.1-C.sub.6haloalkyl. [0103]R.sub.7 is hydrogen, COOH,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
C.sub.1-C.sub.4alkoxycarbonyl or taken together with R.sub.2 to form a
fused, optionally substituted ring. In certain compounds, R.sub.7 is
hydrogen. [0104]Ar.sub.1 is phenyl or 6-membered heteroaryl, each of
which is unsubstituted or substituted ortho to the point of attachment
with 1 or 2 substituents independently chosen from groups of the formula
LR.sub.a. In other words, if Ar.sub.1 is mono-substituted phenyl, the
substitution is at the 2-position; and if Ar.sub.1 is di-substituted
phenyl, the substitutions are located at the 2- and 6-postions.
Similarly, if Ar.sub.1 is substituted pyridin-2-yl, then the substitution
is at the 3-position. Preferred Ar.sub.1 groups are phenyl, pyridyl,
pyrimidinyl, pyrazinyl and pyridazinyl, each of which is unsubstituted or
monosubstituted at the ortho position with halogen, cyano,
C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy or
C.sub.1-C.sub.6haloalkoxy. Particularly preferred groups are phenyl and
pyridyl, optionally substituted as described above. [0105]Ar.sub.2 is 6-
to 10-membered aryl or 5- to 10-membered heteroaryl, each of which is
substituted with from 0 to 6 substituents independently chosen from oxo
and groups of the formula LR.sub.a. In certain embodiments, Ar.sub.2 is
phenyl or a 5- or 6-membered heteroaryl (e.g., a 6-membered heteroaryl),
each of which is substituted with from 0 to 3 substituents independently
selected from (a) groups of the formula LR.sub.a and (b) groups that are
taken together to form a fused, 5- to 7-membered heterocyclic ring that
is substituted with from 0 to 3 substituents independently selected from
R.sub.b. Representative Ar.sub.2 groups include phenyl, pyridyl,
pyrimidinyl, pyrazinyl and pyridazinyl, each of which is substituted with
0, 1 or 2 substituents independently chosen from halogen, cyano,
C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6haloalkyl,
C.sub.1-C.sub.6hydroxyalkyl, C.sub.1-C.sub.6alkyl ether,
C.sub.1-C.sub.6alkanoyl, C.sub.1-C.sub.6alkylsulfonyl,
C.sub.1-C.sub.6haloalkylsulfonyl, amino, and mono- and
di-(C.sub.1-C.sub.6alkyl)amino. Preferably, Ar.sub.2 is phenyl, pyridyl,
pyrimidinyl, pyrazinyl or pyridazinyl that is unsubstituted or
substituted with halogen, cyano, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4hydroxyalkyl, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkylsulfonyl or
C.sub.1-C.sub.4haloalkylsulfonyl. In certain such compounds, Ar.sub.1 is
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
substituted with halogen, cyano, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4haloalkyl; and Ar.sub.2 is pyridyl, pyrimidinyl, pyrazinyl
or pyridazinyl, each of which is substituted with halogen, cyano,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4hydroxyalkyl,
C.sub.1-C.sub.4alkanoyl, C.sub.1-C.sub.4haloalkyl,
C.sub.1-C.sub.4alkylsulfonyl or C.sub.1-C.sub.4haloalkylsulfonyl. [0106]L
is independently selected at each occurrence from a single covalent bond,
O, C(.dbd.O),
##STR00005##
[0106]wherein m is independently selected at each occurrence from 0, 1 and
2; R.sub.x is independently selected at each occurrence from hydrogen,
C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkanoyl and
C.sub.1-C.sub.6alkylsulfonyl; and R.sub.w is hydrogen or
C.sub.1-C.sub.6alkyl; [0107]R.sub.a is independently selected at each
occurrence from: [0108](i) hydrogen, halogen, cyano and nitro; and
[0109](ii) C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl,
C.sub.2-C.sub.8alkynyl, C.sub.1-C.sub.8haloalkyl, C.sub.2-C.sub.8alkyl
ether, mono- and di-(C.sub.1-C.sub.8alkyl)amino and (3- to 10-membered
heterocycle)C.sub.0-C.sub.6alkyl, each of which is substituted with from
0 to 6 substituents independently selected from R.sub.b; and
[0110]R.sub.b is independently chosen at each occurrence from hydroxy,
halogen, amino, aminocarbonyl, cyano, nitro, oxo, COOH,
C.sub.1-C.sub.8alkyl, C.sub.1-C.sub.8alkoxy, C.sub.1-C.sub.8alkylthio,
C.sub.1-C.sub.8alkanoyl, C.sub.1-C.sub.8alkanoyloxy,
C.sub.1-C.sub.8alkoxycarbonyl, C.sub.1-C.sub.8alkyl ether,
C.sub.1-C.sub.8hydroxyalkyl, C.sub.1-C.sub.8haloalkyl,
phenylC.sub.0-C.sub.8alkyl, mono- and
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl,
C.sub.1-C.sub.8alkylsulfonyl and (4- to 7-membered
heterocycle)C.sub.0-C.sub.8alkyl.
[0111]Within certain compounds of Formula II: [0112]Ar.sub.1 is pyridyl,
pyrimidinyl, pyrazinyl or pyridazinyl, each of which is substituted with
halogen, cyano, C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4haloalkyl;
[0113]Ar.sub.2 is phenyl, pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl,
each of which is substituted with halogen, cyano, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4hydroxyalkyl, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkylsulfonyl or
C.sub.1-C.sub.4haloalkylsulfonyl; [0114]R.sub.2 is: [0115](i) hydrogen,
hydroxy or halogen; or [0116](ii) C.sub.1-C.sub.6alkyl,
(C.sub.3-C.sub.7cycloalkyl)C.sub.0-C.sub.4alkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.1-C.sub.6hydroxyalkyl,
C.sub.2-C.sub.6alkyl ether, mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl or (4- to 7-membered
heterocycloalkyl)C.sub.0-C.sub.4alkyl, each of which is substituted with
from 0 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.6haloalkyl;
and [0117]R.sub.7 is hydrogen.
[0118]Certain compounds of Formula II further satisfy Formula IIa
##STR00006##
wherein: [0119]Ar.sub.2 is phenyl or a 6-membered aromatic heterocycle,
each of which is substituted with from 0 to 3 substituents independently
selected from groups of the formula LR.sub.a; [0120]R.sub.2a is hydrogen,
halogen or C.sub.1-C.sub.4alkyl;and the remaining variables are as
described for Formula II.
[0121]Within Formula IIa, representative Ar.sub.2 groups include phenyl,
pyridyl, pyrimidinyl, pyrazinyl and pyridazinyl, each of which is
substituted with 0, 1 or 2 substituents independently selected from
halogen, cyano, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6haloalkyl,
C.sub.1-C.sub.6hydroxyalkyl, C.sub.1-C.sub.6alkyl ether,
C.sub.1-C.sub.6alkanoyl, C.sub.1-C.sub.6alkylsulfonyl,
C.sub.1-C.sub.6haloalkylsulfonyl, amino, mono- and
di-(C.sub.1-C.sub.6alkyl)amino. Within certain embodiments, Ar.sub.2 is
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
unsubstituted or substituted with halogen, cyano, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4hydroxyalkyl, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkylsulfonyl or
C.sub.1-C.sub.4haloalkylsulfonyl. Representative Ar.sub.1 groups are
phenyl, pyridyl, pyrimidinyl, pyrazinyl and pyridazinyl, each of which is
unsubstituted or substituted with halogen, cyano, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy or
C.sub.1-C.sub.6haloalkoxy. In certain such compounds, Ar.sub.1 is
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
substituted with halogen, cyano, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4haloalkyl; and Ar.sub.2 is phenyl, pyridyl, pyrimidinyl,
pyrazinyl or pyridazinyl, each of which is substituted with halogen,
cyano, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4hydroxyalkyl,
C.sub.1-C.sub.4alkanoyl, C.sub.1-C.sub.4haloalkyl,
C.sub.1-C.sub.4alkylsulfonyl or C.sub.1-C.sub.4haloalkylsulfonyl.
[0122]Certain compounds of Formula I further satisfy Formula III
##STR00007##
[0123]Within Formula III, Ar.sub.1, Y, Z, R.sub.2 and R.sub.7 are as
described for Formula I; and Ar.sub.2 is 5-to 10-membered heteroaryl that
substituted with from 0 to 6 substituents independently chosen from oxo
and groups of the formula LR.sub.a, as described above for Formula I.
[0124]In certain compounds of Formula III, each R.sub.1 is hydrogen.
[0125]Within further compounds of Formula III, R.sub.2 is: (i) hydrogen,
hydroxy or halogen; or (ii) C.sub.1-C.sub.6alkyl,
(C.sub.3-C.sub.7cycloalkyl)C.sub.0-C.sub.4alkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.1-C.sub.6hydroxyalkyl,
C.sub.2-C.sub.6alkyl ether, mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl or (4- to 7-membered
heterocycloalkyl)C.sub.0-C.sub.4alkyl, each of which is substituted with
from 0 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.6haloalkyl.
Representative R.sub.2 groups include C.sub.1-C.sub.6alkyl,
C.sub.2-C.sub.6alkyl ether, mono- or di-(C.sub.1-C.sub.6alkyl)amino,
morpholinylC.sub.0-C.sub.2alkyl, piperazinylC.sub.0-C.sub.2alkyl,
piperidinylC.sub.0-C.sub.2alkyl, phenylC.sub.0-C.sub.2alkyl and
pyridylC.sub.0-C.sub.2alkyl, each of which is substituted with from 0 to
4 substituents independently chosen from halogen, cyano, hydroxy, amino,
oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino, C.sub.1-C.sub.6alkyl and
C.sub.1-C.sub.6haloalkyl.
[0126]Within certain compounds of Formula III, Ar.sub.2 is a 5- or
6-membered heteroaryl (e.g., a 6-membered heteroaryl) that is substituted
with from 0 to 3 substituents independently selected from (a) groups of
the formula LR.sub.a and (b) groups that are taken together to form a
fused, 5- to 7-membered heterocyclic ring that is substituted with from 0
to 3 substituents independently selected from R.sub.b. Representative
Ar.sub.2 groups include pyridyl, pyrimidinyl, pyrazinyl and pyridazinyl,
each of which is substituted with 0, 1 or 2 substituents independently
selected from halogen, cyano, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6hydroxyalkyl,
C.sub.1-C.sub.6alkyl ether, C.sub.1-C.sub.6alkanoyl,
C.sub.1-C.sub.6alkylsulfonyl, C.sub.1-C.sub.6haloalkylsulfonyl, amino,
mono- and di-(C.sub.1-C.sub.6alkyl)amino. Preferably, Ar.sub.2 is
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
unsubstituted or substituted with halogen, cyano, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4hydroxyalkyl, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkylsulfonyl or
C.sub.1-C.sub.4haloalkylsulfonyl. Representative Ar.sub.1 groups include
phenyl, pyridyl, pyrimidinyl, pyrazinyl and pyridazinyl, each of which is
unsubstituted or substituted with halogen, cyano, C.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy or
C.sub.1-C.sub.6haloalkoxy. In certain such compounds, Ar.sub.1 is
pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
substituted with halogen, cyano, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4haloalkyl; and Ar.sub.2 is pyridyl, pyrimidinyl, pyrazinyl
or pyridazinyl, each of which is substituted with halogen, cyano,
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4hydroxyalkyl,
C.sub.1-C.sub.4alkanoyl, C.sub.1-C.sub.4haloalkyl,
C.sub.1-C.sub.4alkylsulfonyl or C.sub.1-C.sub.4haloalkylsulfonyl.
[0127]Within further compounds of Formula III: [0128]Ar.sub.1 is pyridyl,
pyrimidinyl, pyrazinyl or pyridazinyl, each of which is substituted with
halogen, cyano, C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4haloalkyl;
[0129]Ar.sub.2 is pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of
which is substituted with halogen, cyano, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4hydroxyalkyl, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkylsulfonyl or
C.sub.1-C.sub.4haloalkylsulfonyl; [0130]Y and Z are independently N or
CH; [0131]R.sub.2 is: [0132](i) hydrogen, hydroxy or halogen; or
[0133](ii) C.sub.1-C.sub.6alkyl,
(C.sub.3-C.sub.7cycloalkyl)C.sub.0-C.sub.4alkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.1-C.sub.6hydroxyalkyl,
C.sub.2-C.sub.6alkyl ether, mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl or (4- to 7-membered
heterocycloalkyl)C.sub.0-C.sub.4alkyl, each of which is substituted with
from 0 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.6haloalkyl;
and [0134]R.sub.7 is hydrogen.
[0135]Certain compounds of Formula I further satisfy Formula IV
##STR00008##
Within Formula IV:
[0136]R.sub.7, Y, Z, Ar.sub.1 and Ar.sub.2 are as described above for
Formula I; andR.sub.2 is: (i) halogen or cyano; [0137](ii) a group of
the formula --R.sub.c-M-A-R.sub.y, wherein: [0138]R.sub.1 is
C.sub.0-C.sub.3alkyl or is joined to R.sub.y or R.sub.z, to form a 4- to
10-membered carbocycle or heterocycle that is substituted with from 0 to
2 substituents independently chosen from R.sub.b; [0139]M is a single
covalent bond, O, S, SO.sub.2, C(.dbd.O), OC(.dbd.O), C(.dbd.O)O,
O--C(.dbd.O)O, C(.dbd.O)N(R.sub.z), OC(.dbd.O)N(R.sub.z),
N(R.sub.z)C(.dbd.O), N(R.sub.z)SO.sub.2, SO.sub.2N(R.sub.z) or
N(R.sub.z); [0140]A is a single covalent bond or C.sub.1-C.sub.8alkyl
substituted with from 0 to 3 substituents independently chosen from
R.sub.b; and [0141]R.sub.y and R.sub.z, if present, are: [0142](a)
independently hydrogen, C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkyl ether,
C.sub.2-C.sub.8alkenyl, a 4-to 10-membered carbocycle or heterocycle, or
joined to R.sub.c to form a 4- to 10-membered carbocycle or heterocycle,
wherein each non-hydrogen R.sub.y and R.sub.z is substituted with from 0
to 6 substituents independently chosen from R.sub.b; or [0143](b) joined
to form a 4- to 10-membered carbocycle or heterocycle that is substituted
with from 0 to 6 substituents independently chosen from R.sub.b;
[0144]such that R.sub.2 is not --NH.sub.2; or [0145](iii) taken
together with R.sub.7 to form a fused 5- to 7-membered ring that is
substituted with from 0 to 3 substituents independently chosen from oxo
and C.sub.1-C.sub.4alkyl.
[0146]Within certain compounds of Formula IV, R.sub.2 is: (i) hydroxy or
halogen; or (ii) C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6aminoalkyl, C.sub.1-C.sub.6hydroxyalkyl,
C.sub.2-C.sub.6alkyl ether, mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl, or (4- to 7-membered
heterocycloalkyl)C.sub.0-C.sub.4alkyl, each of which is substituted with
from 0 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.6haloalkyl.
Representative such R.sub.2 groups include C.sub.1-C.sub.6alkyl,
C.sub.2-C.sub.6alkyl ether, mono- or di-(C.sub.1-C.sub.6alkyl)amino,
morpholinylC.sub.0-C.sub.2alkyl, piperazinylC.sub.0-C.sub.2alkyl,
piperidinylC.sub.0-C.sub.2alkyl, phenylC.sub.0-C.sub.2alkyl and
pyridylC.sub.0-C.sub.2alkyl, each of which is substituted with from 0 to
4 substituents independently chosen from halogen, cyano, hydroxy, amino,
oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino, C.sub.1-C.sub.6alkyl and
C.sub.1-C.sub.6haloalkyl.
[0147]Within certain compounds of Formula IV: [0148]Ar.sub.1 is pyridyl,
pyrimidinyl, pyrazinyl or pyridazinyl, each of which is substituted with
halogen, cyano, C.sub.1-C.sub.4alkyl or C.sub.1-C.sub.4haloalkyl;
[0149]Ar.sub.2 is pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of
which is substituted with halogen, cyano, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4hydroxyalkyl, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4haloalkyl, C.sub.1-C.sub.4alkylsulfonyl or
C.sub.1-C.sub.4haloalkylsulfonyl; [0150]Y and Z are independently N or
CH; [0151]R.sub.2 is: [0152](i) hydroxy or halogen; or [0153](ii)
C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy, C.sub.1-C.sub.6aminoalkyl,
C.sub.1-C.sub.6hydroxyalkyl, C.sub.2-C.sub.6alkyl ether, mono- or
di-(C.sub.1-C.sub.6alkyl)aminoC.sub.0-C.sub.4alkyl or (4- to 7-membered
heterocycloalkyl)C.sub.0-C.sub.4alkyl, each of which is substituted with
from 0 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, oxo, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl C.sub.1-C.sub.6alkoxy and C.sub.1-C.sub.6haloalkyl;
and [0154]R.sub.7 is hydrogen.
[0155]Certain compounds of Formula IV further satisfy Formula IVa
##STR00009##
Within Formula IVa:
[0156]Ar.sub.1, Y and Z are as described for Formula IV; [0157]Ar.sub.2
is phenyl or a 6-membered heteroaryl, each of which is substituted with
from 0 to 3 substituents independently selected from (a) groups of the
formula LR.sub.a and (b) groups that are taken together to form a fused,
5- to 7-membered heterocyclic ring that is substituted with from 0 to 3
substituents independently selected from R.sub.b; [0158]R.sub.3 and
R.sub.4 are: [0159](i) each independently selected from: [0160](a)
hydrogen; and [0161](b) C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl,
C.sub.2-C.sub.8alkynyl, C.sub.1-C.sub.8alkoxy, C.sub.3-C.sub.8alkanone,
C.sub.2-C.sub.8alkanoyl, C.sub.2-C.sub.8alkyl ether,
C.sub.6-C.sub.10arylC.sub.0-C.sub.8alkyl, (5- to 10-membered
heterocycle)C.sub.0-C.sub.8alkyl and C.sub.1-C.sub.8alkylsulfonyl, each
of which is substituted with from 0 to 6 substituents independently
selected from R.sub.b; or [0162](ii) joined to form, with the N to
which they are bound, a 4- to 10-membered heterocyclic group that is
substituted with from 0 to 6 substituents independently selected from
R.sub.b; [0163]R.sub.5 and R.sub.6 are, independently at each
occurrence: [0164](i) each independently selected from hydrogen, hydroxy
and C.sub.1-C.sub.6alkyl; or [0165](ii) taken together to form a keto
group; and [0166]n is 1, 2 or 3.
[0167]In certain compounds of Formula IVa, R.sub.3 and R.sub.4 are each
independently: (i) hydrogen; or (ii) C.sub.1-C.sub.8alkyl,
C.sub.2-C.sub.8alkenyl or C.sub.1-C.sub.8alkylsulfonyl, each of which is
substituted with from 0 to 4 substituents independently selected from
hydroxy, halogen, amino, oxo, COOH, C.sub.1-C.sub.6alkyl,
haloC.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy and
haloC.sub.1-C.sub.6alkoxy. In other compounds of Formula IVa, R.sub.3 and
R.sub.4 are joined to form azetidine, pyrrolidine, morpholine, piperidine
or piperazine, each of which is substituted with from 0 to 4 substituents
independently selected from hydroxy, halogen, amino, oxo, COOH,
C.sub.1-C.sub.6alkyl, haloC.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy and
haloC.sub.1-C.sub.6alkoxy.
[0168]Within certain embodiments, R.sub.3 and R.sub.4 of Formula IVa are
each independently selected from (i) hydrogen or (ii)
C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl,
C.sub.3-C.sub.8alkanone, C.sub.1-C.sub.8alkanoyl, C.sub.2-C.sub.8alkyl
ether, C.sub.6-C.sub.10arylC.sub.0-C.sub.8alkyl, 5- to 10-membered
heterocycleC.sub.0-C.sub.8alkyl and --(SO.sub.2)C.sub.1-C.sub.8alkyl,
each of which is optionally substituted. Within other embodiments,
R.sub.3 and R.sub.4 are each independently selected from (i) hydrogen and
(ii) C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl,
phenylC.sub.0-C.sub.4alkyl, indanylC.sub.0-C.sub.4alkyl, 5- to 6-membered
heteroarylC.sub.0-C.sub.4alkyl and 4- to 7-membered
heterocycloalkylC.sub.0-C.sub.4alkyl, each of which is optionally
substituted with from 1 to 4 substituents independently selected from
hydroxy, halogen, amino, C.sub.1-C.sub.6alkyl, haloC.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6alkoxy and haloC.sub.1-C.sub.6alkoxy. Representative such
R.sub.3 and R.sub.4 groups include C.sub.1-C.sub.6alkyl,
C.sub.2-C.sub.6alkenyl, 5- to 7-membered heterocycloC.sub.0-C.sub.4alkyl,
C.sub.2-C.sub.6alkyl ether, indanyl, benzyl, 1-phenyl-ethyl,
1-phenyl-propyl and 2-phenyl-ethyl, each of which is substituted with
from 0 to 3 substituents independently selected from hydroxy, halogen and
C.sub.1-C.sub.4alkyl. For example, at least one of R.sub.3 and R.sub.4
may be pyridylC.sub.0-C.sub.4alkyl, pyrimidylC.sub.0-C.sub.4alkyl,
imidazolylC.sub.0-C.sub.4alkyl or tetrazolylC.sub.0-C.sub.4alkyl, each of
which is substituted with 0, 1 or 2 substituents. Alternatively, R.sub.3
and/or R.sub.4 may be joined to an R.sub.5 or R.sub.6 group (along with
the N to which R.sub.3 and R.sub.4 are bound and any carbon atoms between
the N and R.sub.5 or R.sub.6) to form an optionally substituted
heterocycle, such as a 5- to 10-membered mono- or bi-cyclic group.
[0169]Within other embodiments, R.sub.3 and/or R.sub.4 of Formula II may
form an optionally substituted heterocycle. For example, R.sub.3 and
R.sub.4 may be joined to form, with the N to which they are bound, an
optionally substituted heterocycle; or R.sub.3 or R.sub.4 may be joined
to an R.sub.5 or R.sub.6 moiety to from an optionally substituted
heterocycle. In either case, the resulting heterocycle may be, for
example, a 4- or 5- to 10-membered, mono- or bi-cyclic group substituted
with from 0 to 4 substituents (e.g., from 1 to 4 substituents or 0, 1 or
2 substituents). In certain embodiments, each substituent is
independently selected from hydroxy, halogen, C.sub.1-C.sub.4alkyl,
haloC.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
haloC.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4alkoxycarbonyl, aminocarbonyl,
heterocycleC.sub.0-C.sub.8alkyl and
heterocycleC.sub.1-C.sub.8alkoxycarbonyl. In certain embodiments, such
substituents are lower alkyl groups such as methyl and/or ethyl.
[0170]A heterocyclic group that comprises R.sub.3 and/or R.sub.4 may be a
heteroaryl group, which comprises an aromatic ring (e.g., optionally
substituted acridinyl, benzimidazolinyl, benzimidazolyl, benzotriazolyl,
carbazolyl, cinnolinyl, indazolyl, indolinyl, indolyl, isoquinolinyl,
quinoxalinyl, naphthyridinyl, phenanthridinyl, phenazinyl,
phenothiazinyl, phenoxazinyl, phthalazinyl, pteridinyl, purinyl,
quinolinyl, quinoxalinyl, quinazolinyl, tetrahydroisoquinolinyl or
tetrahydroquinolinyl). One such heteroaryl is
3,4-dihydro-1H-isoquinolin-2-yl. Alternatively, the heterocycle may be an
optionally substituted heterocycloalkyl group, such as azepanyl,
azocinyl, decahydroquinolinyl, 1,4-dioxa-8-aza-spiro[4.5]dec-8-yl,
imidazolidinyl, imidazolinyl, morpholino, piperadinyl, piperazinyl,
pyridazinyl, pyrazolidinyl, pyrazolinyl, pyrrolidinyl, pyrrolinyl,
thiomorpholino or 1,1-dioxo-thiomorpholin-4-yl. Representative
heterocycles that may be formed from R.sub.3 and R.sub.4 include, but are
not limited to, optionally substituted azepane, azocane,
dihydroisoquinoline, imidazole, morpholine, octahydroquinoline,
piperazine, piperidine and pyrrolidine. Representative heterocycles that
may be formed from R.sub.3 or R.sub.4, in combination with an R.sub.5 or
R.sub.6, include (but are not limited to) optionally substituted
piperadine and pyrrolidine
[0171]R.sub.5 and R.sub.6 of Formula IVa, within certain embodiments, are
independently (at each occurrence) hydrogen or optionally substituted
C.sub.1-C.sub.6alkyl; in addition, or alternatively, any R.sub.5 or
R.sub.6 may be joined with any other R.sub.5 or R.sub.6 to form an
optionally substituted 5- to 7-membered cycloalkyl, or (as discussed
above) joined with R.sub.3 or R.sub.4 to form an optionally substituted
heterocycle. In certain embodiments, each R.sub.5 and R.sub.6 is
C.sub.1-C.sub.2alkyl or hydrogen. n may be 1, 2 or 3, with 1 preferred in
certain embodiments.
[0172]Certain compounds of Formula IV further satisfy Formula IVb
##STR00010##
Within Formula IVb:
[0173]Ar.sub.1, Ar.sub.2, Y and Z are as described for Formula IV;R.sub.3
is selected from: [0174](i) hydrogen; and [0175](ii)
C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl,
C.sub.6-C.sub.10arylC.sub.0-C.sub.8alkyl, and 5- to 10-membered
heterocycleC.sub.0-C.sub.8alkyl, each of which is substituted with from 0
to 6 substituents independently selected from R.sub.b;R.sub.5 and R.sub.6
are, independently at each occurrence:
[0176](i) each independently selected from hydrogen, hydroxy and
C.sub.1-C.sub.6alkyl; or
[0177](ii) taken together to form a keto group; and
n is 1, 2 or 3.
[0178]In certain compounds of Formula IVb, R.sub.3 is: (i) hydrogen; or
(ii) C.sub.1-C.sub.8alkyl substituted with from 0 to 4 substituents
independently selected from hydroxy, halogen, amino, oxo,
C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6alkoxy,
C.sub.1-C.sub.6haloalkoxy and mono- and di-(C.sub.1-C.sub.6alkyl)amino.
Within certain such compounds: [0179]Y and Z are independently N or CH;
[0180]Ar.sub.1 is pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of
which is substituted with halogen, cyano, C.sub.1-C.sub.4alkyl or
C.sub.1-C.sub.4haloalkyl; [0181]Ar.sub.2 is pyridyl, pyrimidinyl,
pyrazinyl or pyridazinyl, each of which is substituted with halogen,
cyano, C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4hydroxyalkyl,
C.sub.1-C.sub.4alkanoyl, C.sub.1-C.sub.4haloalkyl,
C.sub.1-C.sub.4alkylsulfonyl or C.sub.1-C.sub.4haloalkylsulfonyl;
[0182]Each R.sub.5 and R.sub.6 is independently selected from hydrogen
and C.sub.1-C.sub.2alkyl; and [0183]n is 1.
[0184]Within certain embodiments of Formula IVb, R.sub.3 is: (i) hydrogen
or (ii) C.sub.1-C.sub.8alkyl, C.sub.2-C.sub.8alkenyl,
C.sub.2-C.sub.8alkynyl, C.sub.3-C.sub.8alkanone, C.sub.2-C.sub.8alkyl
ether, C.sub.6-C.sub.10arylC.sub.0-C.sub.8alkyl, or 5- to 10-membered
heterocycleC.sub.0-C.sub.8alkyl, each of which is optionally substituted.
Within other embodiments, R.sub.3 of Formula IV is (i) hydrogen or (ii)
C.sub.1-C.sub.6alkyl, C.sub.2-C.sub.6alkyl ether,
phenylC.sub.0-C.sub.4alkyl, 5- to 6-membered
heteroarylC.sub.0-C.sub.4alkyl, or 4- to 7-membered
heterocycloalkylC.sub.0-C.sub.4alkyl, each of which is optionally
substituted with from 1 to 4 substituents independently selected from
hydroxy, halogen, amino, C.sub.1-C.sub.6alkyl, haloC.sub.1-C.sub.6alkyl,
C.sub.1-C.sub.6alkoxy and haloC.sub.1-C.sub.6alkoxy. Representative
R.sub.3 groups include hydrogen, C.sub.1-C.sub.4alkyl,
C.sub.1-C.sub.4alkyl ether and benzyl, each of which is unsubstituted or
substituted with from 1 to 3 substituents independently selected from
hydroxy, halogen and C.sub.1-C.sub.4alkyl. Alternatively, R.sub.3 may be
joined to an R.sub.5 or R.sub.6 group (along with the 0 to which R.sub.3
is bound and any carbon atoms between the O and R.sub.5 or R.sub.6) to
form an optionally substituted heterocycle, such as a 5- to 10-membered
mono- or bi-cyclic group. The resulting heterocycle may, for example, be
substituted with from 0 to 4 (e.g., 0, 1 or 2) substituents independently
chosen from hydroxy, halogen, C.sub.1-C.sub.4alkyl,
haloC.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy,
haloC.sub.1-C.sub.4alkoxy, C.sub.1-C.sub.4alkanoyl,
C.sub.1-C.sub.4alkoxycarbonyl, aminocarbonyl,
heterocycleC.sub.0-C.sub.8alkyl and
heterocycleC.sub.1-C.sub.8alkoxycarbonyl.
[0185]R.sub.5 and R.sub.6, within certain embodiments of Formula III, are
independently (at each occurrence) hydrogen or optionally substituted
C.sub.1-C.sub.6alkyl; in addition, or alternatively, any R.sub.5 or
R.sub.6 may be joined with any other R.sub.5 or R.sub.6 to form an
optionally substituted 5- to 7-membered cycloalkyl, or (as discussed
above) joined with R.sub.3 to form an optionally substituted heterocycle.
In certain embodiments, each R.sub.5 and R.sub.6 is C.sub.1-C.sub.2alkyl
or hydrogen. n may be 1, 2 or 3, with 1 preferred in certain embodiments.
[0186]In certain embodiments of the Formulas provided herein, R.sub.2 is
hydrogen, amino, hydroxy, halogen, or optionally substituted
--(CH.sub.2).sub.nNH.sub.2, --(CH.sub.2).sub.nNH(C.sub.1-C.sub.8alkyl),
--(CH.sub.2).sub.nN(C.sub.1-C.sub.8alkyl).sub.2, --(CH.sub.2).sub.n(5- to
8-membered heterocycloalkyl), --(CH.sub.2).sub.nOH or
--(CH.sub.2).sub.nO(C.sub.1-C.sub.8alkyl). Optionally substituted groups
include, for example, unsubstituted groups and groups substituted with
from 1 to 4 substituents independently chosen from halogen, cyano,
hydroxy, amino, mono- and di-(C.sub.1-C.sub.6alkyl)amino,
C.sub.1-C.sub.6alkyl, and haloC.sub.1-C.sub.6alkyl. Heterocycloalkyl
groups include those in which the heterocycloalkyl comprises a nitrogen
or oxygen atom directly linked to the --(CH.sub.2).sub.n.
[0187]In certain embodiments of the Formulas provided herein, Ar.sub.1 is
phenyl, pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each of which is
unsubstituted or substituted with 1 or 2 substituents as described above;
preferably such substituents, if any, are independently selected from
halogen, hydroxy, cyano, amino, nitro, mono- and
di-(C.sub.1-C.sub.6alkyl)amino, C.sub.1-C.sub.6alkyl,
haloC.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy and
haloC.sub.1-C.sub.6alkoxy. For example, Ar.sub.1 may have one substituent
selected from halogen, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy,
haloC.sub.1-C.sub.6alkyl and haloC.sub.1-C.sub.6alkoxy. Ar.sub.1 groups
include, but are not limited to, pyridin-2-yl, 3-methyl-pyridin-2-yl,
3-trifluoromethyl-pyridin-2-yl and 3-halo-pyridin-2-yl.
[0188]Ar.sub.2, within certain embodiments of the formulas provided
herein, is phenyl, pyridyl, pyrimidinyl, pyrazinyl or pyridazinyl, each
of which is unsubstituted or substituted with 1 or 2 substituents as
described above. In certain embodiments, one such substituent is located
at the para position of a 6-membered Ar.sub.2. Optional Ar.sub.2
substituents are as described above and include, for example, halogen,
hydroxy, cyano, amino, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6haloalkyl,
C.sub.1-C.sub.6hydroxyalkyl, C.sub.1-C.sub.6alkyl ether,
C.sub.2-C.sub.8alkenyl, C.sub.2-C.sub.8alkynyl, C.sub.1-C.sub.6alkanoyl,
C.sub.1-C.sub.6alkylsulfonyl, C.sub.1-C.sub.6haloalkylsulfonyl,
C.sub.1-C.sub.6alkylsulfonamide, C.sub.1-C.sub.6haloalkylsulfonamide,
mono- and di-(C.sub.1-C.sub.6alkyl)amino and 3- to 10-membered
heterocycles. Preferred Ar.sub.2 substituents include
C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4halolkyl and groups of the formula
--(SO.sub.2)R.sub.a, wherein R.sub.a is C.sub.1-C.sub.4alkyl or
haloC.sub.1-C.sub.4alkyl. Ar.sub.2 groups include phenyl, pyridyl,
pyridazinyl, pyrimidinyl, pyrazinyl, pyrrolyl, imidazolyl, pyrazolyl,
oxazolyl, isoxazolyl, thiazolyl, isothiazolyl and thiadiazolyl, each of
which is optionally substituted with 1 or 2 substituents independently
selected from halogen, cyano, C.sub.1-C.sub.6alkyl,
haloC.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6alkoxy,
haloC.sub.1-C.sub.6alkoxy, --SO.sub.2--R.sub.a and
--SO.sub.2NR.sub.x--R.sub.a. Ar.sub.2 groups include, but are not limited
to, phenyl, 2-pyridyl and 3-pyridyl, each of which is substituted at the
para-position with halogen, cyano, methyl, ethyl, propyl, isopropyl,
t-butyl, trifluoromethyl, 2,2,2-trifluoroethyl,
2,2,2-trifluoro-1-methyl-ethyl, methanesulfonyl, ethanesulfonyl,
propanesulfonyl, propane-2-sulfonyl, trifluoromethanesulfonyl or
2,2,2-trifluoroethanesulfonyl.
[0189]Representative compounds provided herein include, but are not
limited to, those specifically described in Examples 1-3. It will be
apparent that the specific compounds recited herein are representative
only, and are not intended to limit the scope of the present invention.
Further, as noted above, all compounds of the present invention may be
present as a free acid or base or as a pharmaceutically acceptable salt.
[0190]Within certain aspects of the present invention, substituted
quinolin-4-ylamine analogues provided herein detectably alter (modulate)
VR1 activity, as determined using an in vitro VR1 functional assay such
as a calcium mobilization assay, dorsal root ganglion assay or in vivo
pain relief assay. As an initial screen for such activity, a VR1 ligand
binding assay may be used. References herein to a "VR1 ligand binding
assay" are intended to refer to a standard in vitro receptor binding
assay such as that provided in Example 5, and a "calcium mobilization
assay" (also referred to herein as a "signal transduction assay") may be
performed as described in Example 6. Briefly, to assess binding to VR1, a
competition assay may be performed in which a VR1 preparation is
incubated with labeled (e.g., .sup.125I or .sup.3H) compound that binds
to VR1 (e.g., a capsaicin receptor agonist such as RTX) and unlabeled
test compound. Within the assays provided herein, the VR1 used is
preferably mammalian VR1, more preferably human or rat VR1. The receptor
may be recombinantly expressed or naturally expressed. The VR1
preparation may be, for example, a membrane preparation from HEK293 or
CHO cells that recombinantly express human VR1. Incubation with a
compound that detectably modulates vanilloid ligand binding to VR1
results in a decrease or increase in the amount of label bound to the VR1
preparation, relative to the amount of label bound in the absence of the
compound. This decrease or increase may be used to determine the K.sub.i
at VR1 as described herein. In general, compounds that decrease the
amount of label bound to the VR1 preparation within such an assay are
preferred.
[0191]As noted above, compounds that are VR1 antagonists are preferred
within certain embodiments. IC.sub.50 values for such compounds may be
determined using a standard in vitro VR1-mediated calcium mobilization
assay, as provided in Example 6. Briefly, cells expressing capsaicin
receptor are contacted with a compound of interest and with an indicator
of intracellular calcium concentration (e.g., a membrane permeable
calcium sensitivity dye such as Fluo-3 or Fura-2 (both of which are
available, for example, from Molecular Probes, Eugene, Oreg.), each of
which produce a fluorescent signal when bound to Ca.sup.++). Such contact
is preferably carried out by one or more incubations of the cells in
buffer or culture medium comprising either or both of the compound and
the indicator in solution. Contact is maintained for an amount of time
sufficient to allow the dye to enter the cells (e.g., 1-2 hours). Cells
are washed or filtered to remove excess dye and are then contacted with a
vanilloid receptor agonist (e.g., capsaicin, RTX or olvanil), typically
at a concentration equal to the EC.sub.50 concentration, and a
fluorescence response is measured. When agonist-contacted cells are
contacted with a compound that is a VR1 antagonist the fluorescence
response is generally reduced by at least 20%, preferably at least 50%
and more preferably at least 80%, as compared to cells that are contacted
with the agonist in the absence of test compound. The IC.sub.50 for VR1
antagonists provided herein is preferably less than 1 micromolar, less
than 100 nM, less than 10 nM or less than 1 nM.
[0192]In other embodiments, compounds that are capsaicin receptor agonists
are preferred. Capsaicin receptor agonist activity may generally be
determined as described in Example 6. When cells are contacted with 1
micromolar of a compound that is a VR1 agonist, the fluorescence response
is generally increased by an amount that is at least 30% of the increase
observed when cells are contacted with 100 nM capsaicin. The EC.sub.50
for VR1 agonists provided herein is preferably less than 1 micromolar,
less than 100 nM or less than 10 nM.
[0193]VR1 modulating activity may also, or alternatively, be assessed
using a cultured dorsal root ganglion assay as provided in Example 9
and/or an in vivo pain relief assay as provided in Example 10. Compounds
provided herein preferably have a statistically significant specific
effect on VR1 activity within one or more functional assays provided
herein.
[0194]Within certain embodiments, VR1 modulators provided herein do not
substantially modulate ligand binding to other cell surface receptors,
such as EGF receptor tyrosine kinase or the nicotinic acetylcholine
receptor. In other words, such modulators do not substantially inhibit
activity of a cell surface receptor such as the human epidermal growth
factor (EGF) receptor tyrosine kinase or the nicotinic acetylcholine
receptor (e.g., the IC.sub.50 or IC.sub.40 at such a receptor is
preferably greater than 1 micromolar, and most preferably greater than 10
micromolar). Preferably, a modulator does not detectably inhibit EGF
receptor activity or nicotinic acetylcholine receptor activity at a
concentration of 0.5 micromolar, 1 micromolar or more preferably 10
micromolar. Assays for determining cell surface receptor activity are
commercially available, and include the tyrosine kinase assay kits
available from Panvera (Madison, Wis.).
[0195]Preferred compounds provided herein are non-sedating. In other
words, a dose of compound that is twice the minimum dose sufficient to
provide analgesia in an animal model for determining pain relief (such as
a model provided in Example 10, herein) causes only transient (i.e.,
lasting for no more than 1/2 the time that pain relief lasts) or
preferably no statistically significant sedation in an animal model assay
of sedation (using the method described by Fitzgerald et al. (1988)
Toxicology 49 (2-3):433-9). Preferably, a dose that is five times the
minimum dose sufficient to provide analgesia does not produce
statistically significant sedation. More preferably, a compound provided
herein does not produce sedation at intravenous doses of less than 25
mg/kg (preferably less than 10 mg/kg) or at oral doses of less than 140
mg/kg (preferably less than 50 mg/kg, more preferably less than 30
mg/kg).
[0196]If desired, compounds provided herein may be evaluated for certain
pharmacological properties including, but not limited to, oral
bioavailability (preferred compounds are orally bioavailable to an extent
allowing for therapeutically effective concentrations of the compound to
be achieved at oral doses of less than 140 mg/kg, preferably less than 50
mg/kg, more preferably less than 30 mg/kg, even more preferably less than
10 mg/kg, still more preferably less than 1 mg/kg and most preferably
less than 0.1 mg/kg), toxicity (a preferred VR1 modulator is nontoxic
when a capsaicin receptor modulatory amount is administered to a
subject), side effects (a preferred VR1 modulator produces side effects
comparable to placebo when a therapeutically effective amount of the
compound is administered to a subject), serum protein binding and in
vitro and in vivo half-life (a preferred VR1 modulator exhibits an in
vitro half-life that is equal to an in vivo half-life allowing for Q.I.D.
dosing, preferably T.I.D. dosing, more preferably B.I.D. dosing, and most
preferably once-a-day dosing). In addition, differential penetration of
the blood brain barrier may be desirable for VR1 modulators used to treat
pain by modulating CNS VR1 activity such that total daily oral doses as
described above provide such modulation to a therapeutically effective
extent, while low brain levels of VR1 modulators used to treat peripheral
nerve mediated pain may be preferred (i.e., such doses do not provide
brain (e.g., CSF) levels of the compound sufficient to significantly
modulate VR1 activity). Routine assays that are well known in the art may
be used to assess these properties, and identify superior compounds for a
particular use. For example, assays used to predict bioavailability
include transport across human intestinal cell monolayers, including
Caco-2 cell monolayers. Penetration of the blood brain barrier of a
compound in humans may be predicted from the brain levels of the compound
in laboratory animals given the compound (e.g., intravenously). Serum
protein binding may be predicted from albumin binding assays. Compound
half-life is inversely proportional to the frequency of dosage of a
compound. In vitro half-lives of compounds may be predicted from assays
of microsomal half-life as described within Example 7, herein.
[0197]As noted above, preferred compounds provided herein are nontoxic. In
general, the term "nontoxic" as used herein shall be understood in a
relative sense and is intended to refer to any substance that has been
approved by the United States Food and Drug Administration ("FDA") for
administration to mammals (preferably humans) or, in keeping with
established criteria, is susceptible to approval by the FDA for
administration to mammals (preferably humans). In addition, a highly
preferred nontoxic compound generally satisfies one or more of the
following criteria: (1) does not substantially inhibit cellular ATP
production; (2) does not significantly prolong heart QT intervals; (3)
does not cause substantial liver enlargement, and (4) does not cause
substantial release of liver enzymes.
[0198]As used herein, a compound that "does not substantially inhibit
cellular ATP production" is a compound that satisfies the criteria set
forth in Example 8, herein. In other words, cells treated as described in
Example 8 with 100 .mu.M of such a compound exhibit ATP levels that are
at least 50% of the ATP levels detected in untreated cells. In more
highly preferred embodiments, such cells exhibit ATP levels that are at
least 80% of the ATP levels detected in untreated compound that "does not
significantly prolong heart QT intervals" is a compound that does not
result in a statistically significant prolongation of heart QT intervals
(as determined by electrocardiography) in guinea pigs, minipigs or dogs
upon administration of twice the minimum dose yielding a therapeutically
effective in vivo concentration. In certain preferred embodiments, a dose
of 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 40 or 50 mg/kg administered
parenterally or orally does not result in a statistically significant
prolongation of heart QT intervals. By "statistically significant" is
meant results varying from control at the p<0.1 level or more
preferably at the p<0.05 level of significance as measured using a
standard parametric assay of statistical significance such as a student's
T test.
[0199]A compound "does not cause substantial liver enlargement" if daily
treatment of laboratory rodents (e.g., mice or rats) for 5-10 days with
twice the minimum dose that yields a therapeutically effective in vivo
concentration results in an increase in liver to body weight ratio that
is no more than 100% over matched controls. In more highly preferred
embodiments, such doses do not cause liver enlargement of more than 75%
or 50% over matched controls. If non-rodent mammals (e.g., dogs) are
used, such doses should not result in an increase of liver to body weight
ratio of more than 50%, preferably not more than 25%, and more preferably
not more than 10% over matched untreated controls. Preferred doses within
such assays include 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 40 or 50 mg/kg
administered parenterally or orally.
[0200]Similarly, a compound "does not promote substantial release of liver
enzymes" if administration of twice the minimum dose yielding a
therapeutically effective in vivo concentration does not elevate serum
levels of ALT, LDH or AST in laboratory rodents by more than 100% over
matched mock-treated controls. In more highly preferred embodiments, such
doses do not elevate such serum levels by more than 75% or 50% over
matched controls. Alternatively, a compound "does not promote substantial
release of liver enzymes" if, in an in vitro hepatocyte assay,
concentrations (in culture media or other such solutions that are
contacted and incubated with hepatocytes in vitro) equivalent to two-fold
the minimum in vivo therapeutic concentration of the compound do not
cause detectable release of any of such liver enzymes into culture medium
above baseline levels seen in media from matched mock-treated control
cells. In more highly preferred embodiments, there is no detectable
release of any of such liver enzymes into culture medium above baseline
levels when such compound concentrations are five-fold, and preferably
ten-fold the minimum in vivo therapeutic concentration of the compound.
[0201]In other embodiments, certain preferred compounds do not inhibit or
induce microsomal cytochrome P450 enzyme activities, such as CYP1A2
activity, CYP2A6 activity, CYP2C9 activity, CYP2C19 activity, CYP2D6
activity, CYP2E1 activity or CYP3A4 activity at a concentration equal to
the minimum therapeutically effective in vivo concentration.
[0202]Certain preferred compounds are not clastogenic (e.g., as determined
using a mouse erythrocyte precursor cell micronucleus assay, an Ames
micronucleus assay, a spiral micronucleus assay or the like) at a
concentration equal to the minimum therapeutically effective in vivo
concentration. In other embodiments, certain preferred compounds do not
induce sister chromatid exchange (e.g., in Chinese hamster ovary cells)
at such concentrations.
[0203]For detection purposes, as discussed in more detail below, VR1
modulators provided herein may be isotopically-labeled or radiolabeled.
For example, compounds recited in Formulas I-III may have one or more
atoms replaced by an atom of the same element having an atomic mass or
mass number different from the atomic mass or mass number usually found
in nature. Examples of isotopes that can be present in the compounds
provided herein include isotopes of hydrogen, carbon, nitrogen, oxygen,
phosphorous, fluorine and chlorine, such as .sup.2H, .sup.3H, .sup.11C,
.sup.13C, .sup.14C, .sup.15N, .sup.18O, .sup.17O, .sup.31P, .sup.32P,
.sup.35S, .sup.18F and .sup.36Cl. In addition, substitution with heavy
isotopes such as deuterium (i.e., 2H) can afford certain therapeutic
advantages resulting from greater metabolic stability, for example
increased in vivo half-life or reduced dosage requirements and, hence,
may be preferred in some circumstances.
Preparation of Substituted Quinolin-4-Ylamine Analogues
[0204]Substituted quinolin-4-ylamine analogues may generally be prepared
using standard synthetic methods. Starting materials are commercially
available from suppliers such as Sigma-Aldrich Corp. (St. Louis, Mo.), or
may be synthesized from commercially available precursors using
established protocols. By way of example, a synthetic route similar to
that shown in any of the following Schemes may be used, together with
synthetic methods known in the art of synthetic organic chemistry. Each
variable in the following schemes refers to any group consistent with the
description of the compounds provided herein.
[0205]Other definitions used in the following Schemes and in the Examples
are:
Ac.sub.2O acetic anhydrideAcOH acetic acidCDCl.sub.3 deuterated
chloroform.delta. chemical shiftDME ethylene glycol dimethyl etherDMF
dimethylformamideDPPF 1,1'-bis(diphenylphosphino)ferroceneEDCl
1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochlorideEt ethylEtOH
ethanol.sup.1H NMR proton nuclear magnetic resonanceHPLC high pressure
liquid chromatographyHz hertziPr isopropyliPrOH isopropanolLCMS liquid
chromatography/mass spectrometryKHMDS potassium
bis(trimethylsilyl)amideMS mass spectrometry(M+1) mass+1KtBuO potassium
tert-butoxideMeOH methanolTHF tetrahydrofuranPd.sub.2(dba).sub.3
tris[dibenzylidineacetone]di-palladiumPd(PPh.sub.3).sub.4
tetrakis(triphenylphosphine) palladium (0)Xantphos
4,5-bis(diphenylphosphino)-9,9-dimethyl-xanthene
##STR00011##
##STR00012##
##STR00013##
##STR00014##
##STR00015##
##STR00016##
##STR00017##
##STR00018## ##STR00019##
##STR00020##
##STR00021## ##STR00022##
##STR00023##
[0206]In certain embodiments, a compound provided herein may contain one
or more asymmetric carbon atoms, so that the compound can exist in
different stereoisomeric forms. Such forms can be, for example, racemates
or optically active forms. As noted above, all stereoisomers are
encompassed by the present invention. Nonetheless, it may be desirable to
obtain single enantiomers (i.e., optically active forms). Standard
methods for preparing single enantiomers include asymmetric synthesis and
resolution of the racemates. Resolution of the racemates can be
accomplished, for example, by conventional methods such as
crystallization in the presence of a resolving agent, or chromatography
using, for example a chiral HPLC column.
[0207]Compounds may be radiolabeled by carrying out their synthesis using
precursors comprising at least one atom that is a radioisotope. Each
radioisotope is preferably carbon (e.g., .sup.14C), hydrogen (e.g.,
.sup.3H), sulfur (e.g., .sup.35S), or iodine (e.g., .sup.125I). Tritium
labeled compounds may also be prepared catalytically via
platinum-catalyzed exchange in tritiated acetic acid, acid-catalyzed
exchange in tritiated trifluoroacetic acid, or heterogeneous-catalyzed
exchange with tritium gas using the compound as substrate. In addition,
certain precursors may be subjected to tritium-halogen exchange with
tritium gas, tritium gas reduction of unsaturated bonds, or reduction
using sodium borotritide, as appropriate. Preparation of radiolabeled
compounds may be conveniently performed by a radioisotope supplier
specializing in custom synthesis of radiolabeled probe compounds.
Pharmaceutical Compositions
[0208]The present invention also provides pharmaceutical compositions
comprising one or more substituted quinolin-4-ylamine analogues, together
with at least one physiologically acceptable carrier or excipient.
Pharmaceutical compositions may comprise, for example, one or more of
water, buffers (e.g., neutral buffered saline or phosphate buffered
saline), ethanol, mineral oil, vegetable oil, dimethylsulfoxide,
carbohydrates (e.g., glucose, mannose, sucrose or dextrans), mannitol,
proteins, adjuvants, polypeptides or amino acids such as glycine,
antioxidants, chelating agents such as EDTA or glutathione and/or
preservatives. In addition, other active ingredients may (but need not)
be included in the pharmaceutical compositions provided herein.
[0209]Pharmaceutical compositions may be formulated for any appropriate
manner of administration, including, for example, topical, oral, nasal,
rectal or parenteral administration. The term parenteral as used herein
includes subcutaneous, intradermal, intravascular (e.g., intravenous),
intramuscular, spinal, intracranial, intrathecal and intraperitoneal
injection, as well as any similar injection or infusion technique. In
certain embodiments, compositions suitable for oral use are preferred.
Such compositions include, for example, tablets, troches, lozenges,
aqueous or oily suspensions, dispersible powders or granules, emulsion,
hard or soft capsules, or syrups or elixirs. Within yet other
embodiments, compositions of the present invention may be formulated as a
lyophilizate. Formulation for topical administration may be preferred for
certain conditions (e.g., in the treatment of skin conditions such as
burns or itch). Formulation for direct administration into the bladder
(intravesicular administration) may be preferred for treatment of urinary
incontinence and overactive bladder.
[0210]Compositions intended for oral use may further comprise one or more
components such as sweetening agents, flavoring agents, coloring agents
and/or preserving agents in order to provide appealing and palatable
preparations. Tablets contain the active ingredient in admixture with
physiologically acceptable excipients that are suitable for the
manufacture of tablets. Such excipients include, for example, inert
diluents (e.g., calcium carbonate, sodium carbonate, lactose, calcium
phosphate or sodium phosphate), granulating and disintegrating agents
(e.g., corn starch or alginic acid), binding agents (e.g., starch,
gelatin or acacia) and lubricating agents (e.g., magnesium stearate,
stearic acid or talc). The tablets may be uncoated or they may be coated
by known techniques to delay disintegration and absorption in the
gastrointestinal tract and thereby provide a sustained action over a
longer period. For example, a time delay material such as glyceryl
monosterate or glyceryl distearate may be employed.
[0211]Formulations for oral use may also be presented as hard gelatin
capsules wherein the active ingredient is mixed with an inert solid
diluent (e.g., calcium carbonate, calcium phosphate or kaolin), or as
soft gelatin capsules wherein the active ingredient is mixed with water
or an oil medium (e.g., peanut oil, liquid paraffin or olive oil).
[0212]Aqueous suspensions contain the active material(s) in admixture with
excipients suitable for the manufacture of aqueous suspensions. Such
excipients include suspending agents (e.g., sodium
carboxymethylcellulose, methylcellulose, hydropropylmethylcellulose,
sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia);
and dispersing or wetting agents (e.g., naturally-occurring phosphatides
such as lecithin, condensation products of an alkylene oxide with fatty
acids such as polyoxyethylene stearate, condensation products of ethylene
oxide with long chain aliphatic alcohols such as
heptadecaethyleneoxycetanol, condensation products of ethylene oxide with
partial esters derived from fatty acids and a hexitol such as
polyoxyethylene sorbitol monooleate, or condensation products of ethylene
oxide with partial esters derived from fatty acids and hexitol anhydrides
such as polyethylene sorbitan monooleate). Aqueous suspensions may also
comprise one or more preservatives, such as ethyl or n-propyl
p-hydroxybenzoate, one or more coloring agents, one or more flavoring
agents, and one or more sweetening agents, such as sucrose or saccharin.
[0213]Oily suspensions may be formulated by suspending the active
ingredient(s) in a vegetable oil (e.g., arachis oil, olive oil, sesame
oil or coconut oil) or in a mineral oil such as liquid paraffin. The oily
suspensions may contain a thickening agent such as beeswax, hard paraffin
or cetyl alcohol. Sweetening agents such as those set forth above, and/or
flavoring agents may be added to provide palatable oral preparations.
Such suspensions may be preserved by the addition of an anti-oxidant such
as ascorbic acid.
[0214]Dispersible powders and granules suitable for preparation of an
aqueous suspension by the addition of water provide the active ingredient
in admixture with a dispersing or wetting agent, suspending agent and one
or more preservatives. Suitable dispersing or wetting agents and
suspending agents are exemplified by those already mentioned above.
Additional excipients, such as sweetening, flavoring and coloring agents,
may also be present.
[0215]Pharmaceutical compositions may also be formulated as oil-in-water
emulsions. The oily phase may be a vegetable oil (e.g., olive oil or
arachis oil), a mineral oil (e.g., liquid paraffin) or a mixture thereof.
Suitable emulsifying agents include naturally-occurring gums (e.g., gum
acacia or gum tragacanth), naturally-occurring phosphatides (e.g., soy
bean lecithin, and esters or partial esters derived from fatty acids and
hexitol), anhydrides (e.g., sorbitan monoleate) and condensation products
of partial esters derived from fatty acids and hexitol with ethylene
oxide (e.g., polyoxyethylene sorbitan monoleate). An emulsion may also
comprise one or more sweetening and/or flavoring agents.
[0216]Syrups and elixirs may be formulated with sweetening agents, such as
glycerol, propylene glycol, sorbitol or sucrose. Such formulations may
also comprise one or more demulcents, preservatives, flavoring agents
and/or coloring agents.
[0217]Formulations for topical administration typically comprise a topical
vehicle combined with active agent(s), with or without additional
optional components. Suitable topical vehicles and additional components
are well known in the art, and it will be apparent that the choice of a
vehicle will depend on the particular physical form and mode of delivery.
Topical vehicles include water; organic solvents such as alcohols (e.g.,
ethanol or isopropyl alcohol) or glycerin; glycols (e.g., butylene,
isoprene or propylene glycol); aliphatic alcohols (e.g., lanolin);
mixtures of water and organic solvents and mixtures of organic solvents
such as alcohol and glycerin; lipid-based materials such as fatty acids,
acylglycerols (including oils, such as mineral oil, and fats of natural
or synthetic origin), phosphoglycerides, sphingolipids and waxes;
protein-based materials such as collagen and gelatin; silicone-based
materials (both non-volatile and volatile); and hydrocarbon-based
materials such as microsponges and polymer matrices. A composition may
further include one or more components adapted to improve the stability
or effectiveness of the applied formulation, such as stabilizing agents,
suspending agents, emulsifying agents, viscosity adjusters, gelling
agents, preservatives, antioxidants, skin penetration enhancers,
moisturizers and sustained release materials. Examples of such components
are described in Martindale--The Extra Pharmacopoeia (Pharmaceutical
Press, London 1993) and Martin (ed.), Remington's Pharmaceutical
Sciences. Formulations may comprise microcapsules, such as
hydroxymethylcellulose or gelatin-microcapsules, liposomes, albumin
microspheres, microemulsions, nanoparticles or nanocapsules.
[0218]A topical formulation may be prepared in a variety of physical forms
including, for example, solids, pastes, creams, foams, lotions, gels,
powders, aqueous liquids and emulsions. The physical appearance and
viscosity of such forms can be governed by the presence and amount of
emulsifier(s) and viscosity adjuster(s) present in the formulation.
Solids are generally firm and non-pourable and commonly are formulated as
bars or sticks, or in particulate form; solids can be opaque or
transparent, and optionally can contain solvents, emulsifiers,
moisturizers, emollients, fragrances, dyes/colorants, preservatives and
other active ingredients that increase or enhance the efficacy of the
final product. Creams and lotions are often similar to one another,
differing mainly in their viscosity; both lotions and creams may be
opaque, translucent or clear and often contain emulsifiers, solvents, and
viscosity adjusting agents, as well as moisturizers, emollients,
fragrances, dyes/colorants, preservatives and other active ingredients
that increase or enhance the efficacy of the final product. Gels can be
prepared with a range of viscosities, from thick or high viscosity to
thin or low viscosity. These formulations, like those of lotions and
creams, may also contain solvents, emulsifiers, moisturizers, emollients,
fragrances, dyes/colorants, preservatives and other active ingredients
that increase or enhance the efficacy of the final product. Liquids are
thinner than creams, lotions, or gels and often do not contain
emulsifiers. Liquid topical products often contain solvents, emulsifiers,
moisturizers, emollients, fragrances, dyes/colorants, preservatives and
other active ingredients that increase or enhance the efficacy of the
final product.
[0219]Suitable emulsifiers for use in topical formulations include, but
are not limited to, ionic emulsifiers, cetearyl alcohol, non-ionic
emulsifiers like polyoxyethylene oleyl ether, PEG-40 stearate,
ceteareth-12, ceteareth-20, ceteareth-30, ceteareth alcohol, PEG-100
stearate and glyceryl stearate. Suitable viscosity adjusting agents
include, but are not limited to, protective colloids or non-ionic gums
such as hydroxyethylcellulose, xanthan gum, magnesium aluminum silicate,
silica, microcrystalline wax, beeswax, paraffin, and cetyl palmitate. A
gel composition may be formed by the addition of a gelling agent such as
chitosan, methyl cellulose, ethyl cellulose, polyvinyl alcohol,
polyquaterniums, hydroxyethylcellulose, hydroxypropylcellulose,
hydroxypropylmethylcellulose, carbomer or ammoniated glycyrrhizinate.
Suitable surfactants include, but are not limited to, nonionic,
amphoteric, ionic and anionic surfactants. For example, one or more of
dimethicone copolyol, polysorbate 20, polysorbate 40, polysorbate 60,
polysorbate 80, lauramide DEA, cocamide DEA, and cocamide MEA, oleyl
betaine, cocamidopropyl phosphatidyl PG-dimonium chloride, and ammonium
laureth sulfate may be used within topical formulations. Suitable
preservatives include, but are not limited to, antimicrobials such as
methylparaben, propylparaben, sorbic acid, benzoic acid, and
formaldehyde, as well as physical stabilizers and antioxidants such as
vitamin E, sodium ascorbate/ascorbic acid and propyl gallate. Suitable
moisturizers include, but are not limited to, lactic acid and other
hydroxy acids and their salts, glycerin, propylene glycol, and butylene
glycol. Suitable emollients include lanolin alcohol, lanolin, lanolin
derivatives, cholesterol, petrolatum, isostearyl neopentanoate and
mineral oils. Suitable fragrances and colors include, but are not limited
to, FD&C Red No. 40 and FD&C Yellow No. 5. Other suitable additional
ingredients that may be included a topical formulation include, but are
not limited to, abrasives, absorbents, anti-caking agents, anti-foaming
agents, anti-static agents, astringents (e.g., witch hazel, alcohol and
herbal extracts such as chamomile extract), binders/excipients, buffering
agents, chelating agents, film forming agents, conditioning agents,
propellants, opacifying agents, pH adjusters and protectants.
[0220]An example of a suitable topical vehicle for formulation of a gel
is: hydroxypropylcellulose (2.1%); 70/30 isopropyl alcohol/water (90.9%);
propylene glycol (5.1%); and Polysorbate 80 (1.9%). An example of a
suitable topical vehicle for formulation as a foam is: cetyl alcohol
(1.1%); stearyl alcohol (0.5%; Quaternium 52 (1.0%); propylene glycol
(2.0%); Ethanol 95 PGF3 (61.05%); deionized water (30.05%); P75
hydrocarbon propellant (4.30%). All percents are by weight.
[0221]Typical modes of delivery for topical compositions include
application using the fingers; application using a physical applicator
such as a cloth, tissue, swab, stick or brush; spraying (including mist,
aerosol or foam spraying); dropper application; sprinkling; soaking; and
rinsing. Controlled release vehicles can also be used.
[0222]A pharmaceutical composition may be prepared as a sterile injectible
aqueous or oleaginous suspension. The modulator, depending on the vehicle
and concentration used, can either be suspended or dissolved in the
vehicle. Such a composition may be formulated according to the known art
using suitable dispersing, wetting agents and/or suspending agents such
as those mentioned above. Among the acceptable vehicles and solvents that
may be employed are water, 1,3-butanediol, Ringer's solution and isotonic
sodium chloride solution. In addition, sterile, fixed oils may be
employed as a solvent or suspending medium. For this purpose any bland
fixed oil may be employed, including synthetic mono- or diglycerides. In
addition, fatty acids such as oleic acid find use in the preparation of
injectible compositions, and adjuvants such as local anesthetics,
preservatives and/or buffering agents can be dissolved in the vehicle.
[0223]Compounds may also be formulated as suppositories (e.g., for rectal
administration). Such compositions can be prepared by mixing the drug
with a suitable non-irritating excipient that is solid at ordinary
temperatures but liquid at the rectal temperature and will therefore melt
in the rectum to release the drug. Suitable excipients include, for
example, cocoa butter and polyethylene glycols.
[0224]Pharmaceutical compositions may be formulated as sustained release
formulations (i.e., a formulation such as a capsule that effects a slow
release of modulator following administration). Such formulations may
generally be prepared using well known technology and administered by,
for example, oral, rectal or subcutaneous implantation, or by
implantation at the desired target site. Carriers for use within such
formulations are biocompatible, and may also be biodegradable; preferably
the formulation provides a relatively constant level of modulator
release. The amount of modulator contained within a sustained release
formulation depends upon, for example, the site of implantation, the rate
and expected duration of release and the nature of the condition to be
treated or prevented.
[0225]In addition to or together with the above modes of administration, a
modulator may be conveniently added to food or drinking water (e.g., for
administration to non-human animals including companion animals (such as
dogs and cats) and livestock). Animal feed and drinking water
compositions may be formulated so that the animal takes in an appropriate
quantity of the composition along with its diet. It may also be
convenient to present the composition as a premix for addition to feed or
drinking water.
[0226]VR1 modulators are generally administered in a capsaicin receptor
modulatory amount, and preferably a therapeutically effective amount.
Preferred systemic doses are no higher than 50 mg per kilogram of body
weight per day (e.g., ranging from about 0.001 mg to about 50 mg per
kilogram of body weight per day), with oral doses generally being about
5-20 fold higher than intravenous doses (e.g., ranging from 0.01 to 40 mg
per kilogram of body weight per day).
[0227]The amount of active ingredient that may be combined with the
carrier materials to produce a single dosage unit will vary depending,
for example, upon the patient being treated and the particular mode of
administration. Dosage units will generally contain between from about 10
.mu.g to about 500 mg of an active ingredient. Optimal dosages may be
established using routine testing, and procedures that are well known in
the art.
[0228]Pharmaceutical compositions may be packaged for treating conditions
responsive to VR1 modulation (e.g., treatment of exposure to vanilloid
ligand, pain, itch, obesity or urinary incontinence). Packaged
pharmaceutical compositions may include a container holding a
therapeutically effective amount of at least one VR1 modulator as
described herein and instructions (e.g., labeling) indicating that the
contained composition is to be used for treating a condition responsive
to VR1 modulation in the patient.
Methods of Use
[0229]Compounds provided herein may be used to alter activity and/or
activation of capsaicin receptors in a variety of contexts, both in vitro
and in vivo. Within certain aspects, VR1 antagonists may be used to
inhibit the binding of vanilloid ligand agonist (such as capsaicin and/or
RTX) to capsaicin receptor in vitro or in vivo. In general, such methods
comprise the step of contacting a capsaicin receptor with a capsaicin
receptor modulatory amount of one or more VR1 modulators provided herein,
in the presence of vanilloid ligand in aqueous solution and under
conditions otherwise suitable for binding of the ligand to capsaicin
receptor. The capsaicin receptor may be present in solution or suspension
(e.g., in an isolated membrane or cell preparation), or in a cultured or
isolated cell. Within certain embodiments, the capsaicin receptor is
expressed by a neuronal cell present in a patient, and the aqueous
solution is a body fluid. Preferably, one or more VR1 modulators are
administered to an animal in an amount such that the analogue is present
in at least one body fluid of the animal at a therapeutically effective
concentration that is 1 micromolar or less; preferably 500 nanomolar or
less; more preferably 100 nanomolar or less, 50 nanomolar or less, 20
nanomolar or less, or 10 nanomolar or less. For example, such compounds
may be administered at a dose that is less than 20 mg/kg body weight,
preferably less than 5 mg/kg and, in some instances, less than 1 mg/kg.
[0230]Also provided herein are methods for modulating, preferably
reducing, the signal-transducing activity (i.e., the calcium conductance)
of a cellular capsaicin receptor. Such modulation may be achieved by
contacting a capsaicin receptor (either in vitro or in vivo) with a
capsaicin receptor modulatory amount of one or more VR1 modulators
provided herein under conditions suitable for binding of the modulator(s)
to the receptor. The receptor may be present in solution or suspension,
in a cultured or isolated cell preparation or in a cell within a patient.
For example, the cell may be a neuronal cell that is contacted in vivo in
an animal. Alternatively, the cell may be an epithelial cell, such as a
urinary bladder epithelial cell (urothelial cell) or an airway epithelial
cell that is contacted in vivo in an animal. Modulation of signal
tranducing activity may be assessed by detecting an effect on calcium ion
conductance (also referred to as calcium mobilization or flux).
Modulation of signal transducing activity may alternatively be assessed
by detecting an alteration of a symptom (e.g., pain, burning sensation,
broncho-constriction, inflammation, cough, hiccup, itch, urinary
incontinence or overactive bladder) of a patient being treated with one
or more VR1 modulators provided herein.
[0231]VR1 modulator(s) provided herein are preferably administered to a
patient (e.g., a human) orally or topically, and are present within at
least one body fluid of the animal while modulating VR1
signal-transducing activity. Preferred VR1 modulators for use in such
methods modulate VR1 signal-transducing activity in vitro at a
concentration of 1 nanomolar or less, preferably 100 picomolar or less,
more preferably 20 picomolar or less, and in vivo at a concentration of 1
micromolar or less, 500 nanomolar or less, or 100 nanomolar or less in a
body fluid such as blood.
[0232]The present invention further provides methods for treating
conditions responsive to VR1 modulation. Within the context of the
present invention, the term "treatment" encompasses both
disease-modifying treatment and symptomatic treatment, either of which
may be prophylactic (i.e., before the onset of symptoms, in order to
prevent, delay or reduce the severity of symptoms) or therapeutic (i.e.,
after the onset of symptoms, in order to reduce the severity and/or
duration of symptoms). A condition is "responsive to VR1 modulation" if
it is characterized by inappropriate activity of a capsaicin receptor,
regardless of the amount of vanilloid ligand present locally, and/or if
modulation of capsaicin receptor activity results in alleviation of the
condition or a symptom thereof. Such conditions include, for example,
symptoms resulting from exposure to VR1-activating stimuli, pain,
respiratory disorders such as asthma and chronic obstructive pulmonary
disease, itch, urinary incontinence, overactive bladder, cough, hiccup,
and obesity, as described in more detail below. Such conditions may be
diagnosed and monitored using criteria that have been established in the
art. Patients may include humans, domesticated companion animals and
livestock, with dosages as described above.
[0233]Treatment regimens may vary depending on the compound used and the
particular condition to be treated. However, for treatment of most
disorders, a frequency of administration of 4 times daily or less is
preferred. In general, a dosage regimen of 2 times daily is more
preferred, with once a day dosing particularly preferred. For the
treatment of acute pain, a single dose that rapidly reaches effective
concentrations is desirable. It will be understood, however, that the
specific dose level and treatment regimen for any particular patient will
depend upon a variety of factors including the activity of the specific
compound employed, the age, body weight, general health, sex, diet, time
of administration, route of administration, and rate of excretion, drug
combination and the severity of the particular disease undergoing
therapy. In general, the use of the minimum dose sufficient to provide
effective therapy is preferred. Patients may generally be monitored for
therapeutic effectiveness using medical or veterinary criteria suitable
for the condition being treated or prevented.
[0234]Patients experiencing symptoms resulting from exposure to capsaicin
receptor-activating stimuli include individuals with burns caused by
heat, light, tear gas or acid and those whose mucous membranes are
exposed (e.g., via ingestion, inhalation or eye contact) to capsaicin
(e.g., from
hot peppers or in pepper spray) or a related irritant such as
acid, tear gas or air pollutants. The resulting symptoms (which may be
treated using VR1 modulators, especially antagonists, provided herein)
may include, for example, pain, broncho-constriction and inflammation.
[0235]Pain that may be treated using the VR1 modulators provided herein
may be chronic or acute and includes, but is not limited to, peripheral
nerve-mediated pain (especially neuropathic pain). Compounds provided
herein may be used in the treatment of, for example, postmastectomy pain
syndrome, stump pain, phantom limb pain, oral neuropathic pain, toothache
(dental pain), denture pain, postherpetic neuralgia, diabetic neuropathy,
reflex sympathetic dystrophy, trigeminal neuralgia, osteoarthritis,
rheumatoid arthritis, fibromyalgia, Guillain-Barre syndrome, meralgia
paresthetica, burning-mouth syndrome and/or bilateral peripheral
neuropathy. Additional neuropathic pain conditions include causalgia
(reflex sympathetic dystrophy --RSD, secondary to injury of a peripheral
nerve), neuritis (including, for example, sciatic neuritis, peripheral
neuritis, polyneuritis, optic neuritis, postfebrile neuritis, migrating
neuritis, segmental neuritis and Gombault's neuritis), neuronitis,
neuralgias (e.g., those mentioned above, cervicobrachial neuralgia,
cranial neuralgia, geniculate neuralgia, glossopharyngial neuralgia,
migranous neuralgia, idiopathic neuralgia, intercostals neuralgia,
mammary neuralgia, mandibular joint neuralgia, Morton's neuralgia,
nasociliary neuralgia, occipital neuralgia, red neuralgia, Sluder's
neuralgia, splenopalatine neuralgia, supraorbital neuralgia and vidian
neuralgia), surgery-related pain, musculoskeletal pain, AIDS-related
neuropathy, MS-related neuropathy, and spinal cord injury-related pain.
Headache, including headaches involving peripheral nerve activity, such
as sinus, cluster (i.e., migranous neuralgia) and some tension headaches
and migraine, may also be treated as described herein. For example,
migraine headaches may be prevented by administration of a compound
provided herein as soon as a pre-migrainous aura is experienced by the
patient. Further pain conditions that can be treated as described herein
include "burning mouth syndrome," labor pains, Charcot's pains,
intestinal gas pains, menstrual pain, acute and chronic back pain (e.g.,
lower back pain), hemorrhoidal pain, dyspeptic pains, angina, nerve root
pain, homotopic pain and heterotopic pain--including cancer associated
pain (e.g., in patients with bone cancer), pain (and inflammation)
associated with venom exposure (e.g., due to snake bite, spider bite, or
insect sting) and trauma associated pain (e.g., post-surgical pain, pain
from cuts, bruises and broken bones, and burn pain). Additional pain
conditions that may be treated as described herein include pain
associated with inflammatory bowel disease, irritable bowel syndrome
and/or inflammatory bowel disease.
[0236]Within certain aspects, VR1 modulators provided herein may be used
for the treatment of mechanical pain. As used herein, the term
"mechanical pain" refers to pain other than headache pain that is not
neuropathic or a result of exposure to heat, cold or external chemical
stimuli. Mechanical pain includes physical trauma (other than thermal or
chemical burns or other irritating and/or painful exposures to noxious
chemicals) such as post-surgical pain and pain from cuts, bruises and
broken bones; toothache, denture pain; nerve root pain; osteoarthritis;
rheumatoid arthritis; fibromyalgia; meralgia paresthetica; back pain;
cancer-associated pain; angina; carpel tunnel syndrome; and pain
resulting from bone fracture, labor, hemorrhoids, intestinal gas,
dyspepsia, and menstruation.
[0237]Itching conditions that may be treated include psoriatic pruritis,
itch due to hemodialysis, aguagenic pruritus, and itching associated with
vulvar vestibulitis, contact dermatitis, insect bites and skin allergies.
Urinary tract conditions that may be treated as described herein include
urinary incontinence (including overflow incontinence, urge incontinence
and stress incontinence), as well as overactive or unstable bladder
conditions (including detrusor hyperflexia of spinal origin and bladder
hypersensitivity). In certain such treatment methods, VR1 modulator is
administered via a catheter or similar device, resulting in direct
injection of VR1 modulator into the bladder. Compounds provided herein
may also be used as anti-tussive agents (to prevent, relieve or suppress
coughing) and for the treatment of hiccup, and to promote weight loss in
an obese patient.
[0238]Within other aspects, VR1 modulators provided herein may be used
within combination therapy for the treatment of conditions involving
inflammatory components. Such conditions include, for example, autoimmune
disorders and pathologic autoimmune responses known to have an
inflammatory component including, but not limited to, arthritis
(especially rheumatoid arthritis), psoriasis, Crohn's disease, lupus
erythematosus, irritable bowel syndrome, tissue graft rejection, and
hyperacute rejection of transplanted organs. Other such conditions
include trauma (e.g., injury to the head or spinal cord), cardio- and
cerebo-vascular disease and certain infectious diseases.
[0239]Within such combination therapy, a VR1 modulator is administered to
a patient along with an anti-inflammatory agent. The VR1 modulator and
anti-inflammatory agent may be present in the same pharmaceutical
composition, or may be administered separately in either order.
Anti-inflammatory agents include, for example, non-steroidal
anti-inflammatory drugs (NSAIDs), non-specific and cyclooxygenase-2
(COX-2) specific cyclooxygenase enzyme inhibitors, gold compounds,
corticosteroids, met
hotrexate, tumor necrosis factor (TNF) receptor
antagonists, anti-TNF alpha antibodies, anti-C5 antibodies, and
interleukin-1 (IL-1) receptor antagonists. Examples of NSAIDs include,
but are not limited to ibuprofen (e.g., ADVIL.TM., MOTRIN.TM.),
flurbiprofen (ANSAID.TM.), naproxen or naproxen sodium (e.g., NAPROSYN,
ANAPROX, ALEVE.TM.), diclofenac (e.g., CATAFLAM.TM., VOLTAREN.TM.),
combinations of diclofenac sodium and misoprostol (e.g., ARTHROTEC.TM.),
sulindac (CLINORIL.TM.), oxaprozin (DAYPRO.TM.), diflunisal
(DOLOBID.TM.), piroxicam (FELDENE.TM.), indomethacin (INDOCIN.TM.),
etodolac (LODINE.TM.), fenoprofen calcium (NALFON.TM.), ketoprofen (e.g.,
ORUDIS.TM., ORUVAIL.TM.), sodium nabumetone (RELAFEN.TM.), sulfasalazine
(AZULFIDINE.TM.), tolmetin sodium (TOLECTIN.TM.), and hydroxychloroquine
(PLAQUENIL.TM.). A particular class of NSAIDs consists of compounds that
inhibit cyclooxygenase (COX) enzymes, such as celecoxib (CELEBREX.TM.)
and rofecoxib (VIOXX.TM.). NSAIDs further include salicylates such as
acetylsalicylic acid or aspirin, sodium salicylate, choline and magnesium
salicylates (TRILISATE.TM.), and salsalate (DISALCID.TM.), as well as
corticosteroids such as cortisone (CORTONE.TM. acetate), dexamethasone
(e.g., DECADRON.TM.), methylprednisolone (MEDROL.TM.) prednisolone
(PRELONE.TM.), prednisolone sodium phosphate (PEDIAPRED.TM.), and
prednisone (e.g., PREDNICEN-M.TM., DELTASONE.TM., STERAPRED.TM.).
[0240]Suitable dosages for VR1 modulator within such combination therapy
are generally as described above. Dosages and methods of administration
of anti-inflammatory agents can be found, for example, in the
manufacturer's instructions in the Physician's Desk Reference. In certain
embodiments, the combination administration of a VR1 modulator with an
anti-inflammatory agent results in a reduction of the dosage of the
anti-inflammatory agent required to produce a therapeutic effect. Thus,
preferably, the dosage of anti-inflammatory agent in a combination or
combination treatment method of the invention is less than the maximum
dose advised by the manufacturer for administration of the
anti-inflammatory agent without combination administration of a VR1
antagonist. More preferably this dosage is less than 3/4, even more
preferably less than 1/2, and highly preferably, less than 1/4 of the
maximum dose, while most preferably the dose is less than 10% of the
maximum dose advised by the manufacturer for administration of the
anti-inflammatory agent(s) when administered without combination
administration of a VR1 antagonist. It will be apparent that the dosage
amount of VR1 antagonist component of the combination needed to achieve
the desired effect may similarly be affected by the dosage amount and
potency of the anti-inflammatory agent component of the combination.
[0241]In certain preferred embodiments, the combination administration of
a VR1 modulator with an anti-inflammatory agent is accomplished by
packaging one or more VR1 modulators and one or more anti-inflammatory
agents in the same package, either in separate containers within the
package or in the same contained as a mixture of one or more VR1
antagonists and one or more anti-inflammatory agents. Preferred mixtures
are formulated for oral administration (e.g., as pills, capsules, tablets
or the like). In certain embodiments, the package comprises a label
bearing indicia indicating that the one or more VR1 modulators and one or
more anti-inflammatory agents are to be taken together for the treatment
of an inflammatory pain condition. A highly preferred combination is one
in which the anti-inflammatory agent(s) include at least one COX-2
specific cyclooxygenase enzyme inhibitor such as valdecoxib
(BEXTRA.RTM.), lumiracoxib (PREXIGE.TM.), etoricoxib (ARCOXIA.RTM.),
celecoxib (CELEBREX.RTM.) and/or rofecoxib (VIOXX.RTM.).
[0242]Within further aspects, VR1 modulators provided herein may be used
in combination with one or more additional pain relief medications.
Certain such medications are also anti-inflammatory agents, and are
listed above. Other such medications are narcotic analgesic agents, which
typically act at one or more opioid receptor subtypes (e.g., .mu.,
.kappa. and/or .delta.), preferably as agonists or partial agonists. Such
agents include opiates, opiate derivatives and opioids, as well as
pharmaceutically acceptable salts and hydrates thereof. Specific examples
of narcotic analgesics include, within preferred embodiments, alfentanyl,
alphaprodine, anileridine, bezitramide, buprenorphine, codeine,
diacetyldihydromorphine, diacetylmorphine, dihydrocodeine, diphenoxylate,
ethylmorphine, fentanyl, heroin, hydrocodone, hydromorphone,
isomethadone, levomethorphan, levorphane, levorphanol, meperidine,
metazocine, methadone, methorphan, metopon, morphine, opium extracts,
opium fluid extracts, powdered opium, granulated opium, raw opium,
tincture of opium, oxycodone, oxymorphone, paregoric, pentazocine,
pethidine, phenazocine, piminodine, propoxyphene, racemethorphan,
racemorphan, thebaine and pharmaceutically acceptable salts and hydrates
of the foregoing agents.
[0243]Other examples of narcotic analgesic agents include acetorphine,
acetyldihydrocodeine, acetylmethadol, allylprodine, alphracetylmethadol,
alphameprodine, alphamethadol, benzethidine, benzylmorphine,
betacetylmethadol, betameprodine, betamethadol, betaprodine, butorphanol,
clonitazene, codeine methylbromide, codeine-N-oxide, cyprenorphine,
desomorphine, dextromoramide, diampromide, diethylthiambutene,
dihydromorphine, dimenoxadol, dimepheptanol, dimethylthiamubutene,
dioxaphetyl butyrate, dipipanone, drotebanol, ethanol,
ethylmethylthiambutene, etonitazene, etorphine, etoxeridine, furethidine,
hydromorphinol, hydroxypethidine, ketobemidone, levomoramide,
levophenacylmorphan, methyldesorphine, methyldihydromorphine,
morpheridine, morphine methylpromide, morphine methylsulfonate,
morphine-N-oxide, myrophin, naloxone, nalbuyphine, naltyhexone,
nicocodeine, nicomorphine, noracymethadol, norlevorphanol, normethadone,
normorphine, norpipanone, pentazocaine, phenadoxone, phenampromide,
phenomorphan, phenoperidine, piritramide, pholcodine, proheptazoineii,
properidine, propiran, racemoramide, thebacon, trimeperidine and the
pharmaceutically acceptable salts and hydrates thereof.
[0244]Further specific representative analgesic agents include, for
example: TALWIN.RTM. Nx and DEMEROL.RTM. (both available from Sanofi
Winthrop Pharmaceuticals; New York, N.Y.); LEVO-DROMORAN.RTM.;
BUPRENEX.RTM. (Reckitt & Coleman Pharmaceuticals, Inc.; Richmond, Va.);
MSIR.RTM. (Purdue Pharma L.P.; Norwalk, Conn.); DILAUDID.RTM. (Knoll
Pharmaceutical Co.; Mount Olive, N.J.); SUBLIMAZE.RTM.; SUFENTA.RTM.
(Janssen Pharmaceutica Inc.; Titusville, N.J.); PERCOCET.RTM.,
NUBAIN.RTM. and NUMORPHAN.RTM. (all available from Endo Pharmaceuticals
Inc.; Chadds Ford, Pa.) HYDROSTAT.RTM. IR, MS/S and MS/L (all available
from Richwood Pharmaceutical Co. Inc; Florence, Ky.), ORAMORPH.RTM. SR
and ROXICODONE.RTM. (both available from Roxanne Laboratories; Columbus
Ohio) and STADOL.RTM. (Bristol-Myers Squibb; New York, N.Y.). Still
further analgesic agents include CB2-receptor agonists, such as AM1241,
and compounds that bind to the .alpha.2.delta. subunit, such as Neurontin
(Gabapentin) and pregabalin.
[0245]Suitable dosages for VR1 modulator within such combination therapy
are generally as described above. Dosages and methods of administration
of other pain relief medications can be found, for example, in the
manufacturer's instructions in the Physician's Desk Reference. In certain
embodiments, the combination administration of a VR1 modulator with one
or more additional pain medications results in a reduction of the dosage
of each therapeutic agent required to produce a therapeutic effect (e.g.,
the dosage or one or both agent may less than 3/4, less than 1/2, less
than 1/4 or less than 10% of the maximum dose listed above or advised by
the manufacturer). In certain preferred embodiments, the combination
administration of a VR1 modulator with one or more additional pain relief
medications is accomplished by packaging one or more VR1 modulators and
one or more additional pain relief medications in the same package, as
described above.
[0246]Modulators that are VR1 agonists may further be used, for example,
in crowd control (as a substitute for tear gas) or personal protection
(e.g., in a spray formulation) or as pharmaceutical agents for the
treatment of pain, itch, urinary incontinence or overactive bladder via
capsaicin receptor desensitization. In general, compounds for use in
crowd control or personal protection are formulated and used according to
conventional tear gas or pepper spray technology.
[0247]Within separate aspects, the present invention provides a variety of
non-pharmaceutical in vitro and in vivo uses for the compounds provided
herein. For example, such compounds may be labeled and used as probes for
the detection and localization of capsaicin receptor (in samples such as
cell preparations or tissue sections, preparations or fractions thereof).
In addition, compounds provided herein that comprise a suitable reactive
group (such as an aryl carbonyl, nitro or azide group) may be used in
photoaffinity labeling studies of receptor binding sites. In addition,
compounds provided herein may be used as positive controls in assays for
receptor activity, as standards for determining the ability of a
candidate agent to bind to capsaicin receptor, or as radiotracers for
positron emission tomography (PET) imaging or for single photon emission
computerized tomography (SPECT). Such methods can be used to characterize
capsaicin receptors in living subjects. For example, a VR1 modulator may
be labeled using any of a variety of well known techniques (e.g.,
radiolabeled with a radionuclide such as tritium, as described herein),
and incubated with a sample for a suitable incubation time (e.g.,
determined by first assaying a time course of binding). Following
incubation, unbound compound is removed (e.g., by washing), and bound
compound detected using any method suitable for the label employed (e.g.,
autoradiography or scintillation counting for radiolabeled compounds;
spectroscopic methods may be used to detect luminescent groups and
fluorescent groups). As a control, a matched sample containing labeled
compound and a greater (e.g., 10-fold greater) amount of unlabeled
compound may be processed in the same manner. A greater amount of
detectable label remaining in the test sample than in the control
indicates the presence of capsaicin receptor in the sample. Detection
assays, including receptor autoradiography (receptor mapping) of
capsaicin receptor in cultured cells or tissue samples may be performed
as described by Kuhar in sections 8.1.1 to 8.1.9 of Current Protocols in
Pharmacology (1998) John Wiley & Sons, New York.
[0248]Modulators provided herein may also be used within a variety of well
known cell separation methods. For example, modulators may be linked to
the interior surface of a tissue culture plate or other support, for use
as affinity ligands for immobilizing and thereby isolating, capsaicin
receptors (e.g., isolating receptor-expressing cells) in vitro. Within
one preferred embodiment, a modulator linked to a fluorescent marker,
such as fluorescein, is contacted with the cells, which are then analyzed
(or isolated) by fluorescence activated cell sorting (FACS).
[0249]Modulators provided herein may further be used within assays for the
identification of other agents that bind to capsaicin receptor. In
general, such assays are standard competition binding assays, in which
bound, labeled VR1 modulator is displaced by a test compound. Briefly,
such assays are performed by: (a) contacting capsaicin receptor with a
radiolabeled VR1 modulator as described herein, under conditions that
permit binding of the VR1 modulator to capsaicin receptor, thereby
generating bound, labeled VR1 modulator; (b) detecting a signal that
corresponds to the amount of bound, labeled VR1 modulator in the absence
of test agent; (c) contacting the bound, labeled VR1 modulator with a
test agent; (d) detecting a signal that corresponds to the amount of
bound labeled VR1 modulator in the presence of test agent; and (e)
detecting a decrease in signal detected in step (d), as compared to the
signal detected in step (b), and therefrom identifying an agent that
binds to capsaicin receptor.
[0250]The following Examples are offered by way of illustration and not by
way of limitation. Unless otherwise specified all reagents and solvent
are of standard commercial grade and are used without further
purification. Using routine modifications, the starting materials may be
varied and additional steps employed to produce other compounds provided
herein.
EXAMPLES
[0251]In the following Examples, mass spectroscopy data is Electrospray
MS, obtained in positive ion mode with a 15V or 30V cone voltage, using a
Micromass Time-of-Flight LCT, equipped with a Waters 600 pump, Waters 996
p
hotodiode array detector, Gilson 215 autosampler, and a Gilson 841
microinjector. MassLynx (Advanced Chemistry Development, Inc; Toronto,
Canada) version 4.0 software was used for data collection and analysis.
Sample volume of 1 microliter was injected onto a 50.times.4.6 mm
Chromolith SpeedROD C18 column, and eluted using a 2-phase linear
gradient at 6 ml/min flow rate. Sample was detected using total
absorbance count over the 220-340 nm UV range. The elution conditions
were: Mobile Phase A--95/5/0.05 Water/Methanol/TFA; Mobile Phase
B--5/95/0.025 Water/Methanol/TFA.
TABLE-US-00001
Gradient:
Time(min) % B
0 10
0.5 100
1.2 100
1.21 10
[0252]The total run time was 2 minutes inject to inject.
[0253]For the compounds described in Examples 1 and 2, the IC.sub.50
determined as described in Example 6, herein, is 1 micromolar or less.
Example 1
Preparation of Representative Substituted Quinolin-4-ylamine Analogues
[0254]A. Using the procedure illustrated in Scheme
1,2-methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]napthyridin-4-y-
l-(4-trifluoromethylphenyl)-amine is prepared by the following steps:
1. 2-cyano-3-trifluoromethylpyridine
##STR00024##
[0256]DMF (3500 mL), H.sub.2O (35 mL), 2-chloro-3-trifluoromethyl-pyridine
(250 g; 1.38 mol), Zn(CN).sub.2 (97 g; 0.83 mol), Pd.sub.2(dba).sub.3
(19.0 g) and DPPF (22.4 g) are combined in a 22.0 liter flask. The
reaction mixture is degassed by bubbling N.sub.2 into the reaction
mixture over a period of 30 minutes. The reaction mixture is then heated
to 120.degree. C. for 4.5 hours, at which time an additional 9.5 g of
Pd.sub.2(dba).sub.3 and 11.2 g of DPPF is added to the reaction mixture.
The reaction mixture is then heated at 120.degree. C. for another 2
hours, and then allowed to cool to room temperature overnight. The
resulting dark brown solution is cooled in ice and cold water. A mixture
of saturated NH.sub.4Cl (1380 mL), 28% NH.sub.4OH (345 mL and water (1380
mL) is then added and the mixture is stirred in an ice bath for 1 hour.
To this stirred mixture is added 3.0 liters of EtOAc, and the mixture is
stirred for 15 minutes. The EtOAc layer is separated from the mixture by
suction the extraction is repeated another four times with EtOAc
(2.times.2 liters, 2.times.1.5 liters). The combined EtOAc extracts are
filtered through one inch of celite and dried with Na.sub.2SO.sub.4 (500
g). The dried extract is filtered and concentrated in vacuum at
40.degree. C. initially to a volume of three liters. The mixture is
concentrated at 80.degree. C. under vacuum to afford a dark brown oil,
which is distilled under vacuum to give
2-cyano-3-trifluoromethylpyridine.
2. 2-acetyl-3-trifluoromethylpyridine
##STR00025##
[0258]2-cyano-3-trifluoromethylpyridine (179 g; 1.04 mol) and THF (1200
mL) are combined in a 5.0 liter flask and cooled with and ice and salt
mixture. 3.0 M MeMgI/Et2O (694 mL) is added drop wise over a period of 90
minutes while maintaining the inside temperature of the reaction mixture
below 5.degree. C. After the addition, the reaction mixture is stirred at
0.degree. C. for another 30 minutes, and is then slowly poured over 3.0
kg of crushed ice in a 12 liter vessel with stirring (6.degree. C.). The
undissolved magnesium salts from the original reaction vessel are
quenched with ice (750 g) and transferred to the 12 liter vessel. The
resulting mixture is acidified with 6.0 N aq. HCl to pH 2.0 and stirred
for 30 minutes at <10.degree. C. The mixture is then extracted with
EtOAc (5.times.1 liters), and the combined extracts are washed with brine
(1.5 liters) and dried with Na.sub.2SO.sub.4 (500 g). The dried extract
is filtered and concentrated in vacuum at 40.degree. C. to afford a dark
brown oil. The crude product is distilled under vacuum to give
2-acetyl-3-trifluoromethylpyridine as a clear pale yellow liquid.
3. 3-dimethylamino-1-(3-trifluoromethyl-pyridin-2-yl)-propenone
##STR00026##
[0260]2-acetyl-3-trifluoromethylpyridine (150 g; 0.79 mol) and
(Me).sub.2N--CH(OMe).sub.2 (236 g; 1.98 mol) are combined in a 1 liter
flask. The mixture is heated with stirring at 105.degree. C. for 5 hours.
Excess (Me).sub.2N--CH(OMe).sub.2 is removed under vacuum at 60.degree.
C. and the mixture is dried under high vacuum (0.1 torr) for 1 hour to
yield 3-dimethylamino-1-(3-trifluoromethyl-pyridin-2-yl)-propenone as a
brown oil.
4. 3-amino-3-methoxyacrylonitrile hydrochloride
##STR00027##
[0262]Malononitrile (198 g; 3 mol), HCO.sub.2Me (1.0 L) and MeOH (240 mL)
are added to a 3 liter flask and cooled with an ice and salt mixture.
SOCl.sub.2 is added drop wise over a period of 60 minutes while
maintaining the inside temperature of the reaction mixture below
10.degree. C. After the addition, the reaction mixture is stirred at
0-10.degree. C. for another 60 minutes to yield a yellow solid
suspension. The salt that separated from the mixture is filtered, and the
solid is washed with HCO.sub.2Me (2.times.75 mL) and air dried for 15
minutes. The salt is dried under vacuum at 25.degree. C. for 1 hour to
yield 3-amino-3-methoxyacrylonitrile hydrochloride as a white solid.
5. 6-Amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carbonitrile
##STR00028##
[0264]3-dimethylamino-1-(3-trifluoromethyl-pyridin-2-yl)-propenone (191.7
g; 0.79 mol), EtOH (2000 mL), NH4OAc (302.6 g; 9.93 mol) and
3-amino-3-methoxyacrylonitrile hydrochloride (211.2 g; 1.57 mol) are
combined in a 5 liter flask. The reaction mixture is heated to 80.degree.
C. for 7 hours. The mixture is then allowed to cool to room temperature
and the solvent is removed under reduced pressure. The solid that
separates at this stage is filtered and washed with small amount of cold
EtOH to afford 133 g of light brick solid. The solid is treated with 750
mL of EtOAc and the mixture is washed with saturated NaHCO.sub.3. The
organic extract is dried with Na.sub.2SO.sub.4 (100 g), filtered and
concentrated in vacuum at 40.degree. C. to yield
6-amino-3'-trifluoromethyl-[2,2'] bipyridinyl-5-carbonitrile as a light
brick colored solid.
6. 6-Amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid
##STR00029##
[0266]6-Amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carbonitrile (2.33 g,
8.82 mmol) is dissolved in 12M HCl (50 mL) and heated at 110.degree. C.
overnight. The aqueous acid is removed under reduced pressure to yield
the title compound as its hydrochloride salt.
7. 6-Amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid
2,5-dioxo-pyrrolidin-1-yl ester
##STR00030##
[0268]6-Amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid
hydrochloride (11.33 g, 35.44 mmol), N-hydroxy-succinimide (8.15 g, 70.9
mmol), and EDCl (10.19 g, 53.16 mmol) are dissolved in a solution of dry
THF (100 mL) and Hunig's base (16.12 g, 125 mmol). The reaction mixture
is stirred overnight at room temperature. Ethyl acetate (200 mL) is added
and the organic phase extracted with water (3.times.100 mL) and brine
(100 mL). The organic extract is dried over Na.sub.2SO.sub.4 and the
solvent removed under reduced pressure to yield the title compound as a
brown foam.
8. 4-Hydroxy-2-methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]napth-
yridine-3-carboxylic acid methyl ester
##STR00031##
[0270]A solution of
6-amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid
2,5-dioxo-pyrrolidin-1-yl ester (10.4 g, 27.3 mmol) in 50 mL dry THF is
added in one portion to a mixture of potassium t-butoxide (7.36 g, 65.6
mmol) and methyl 4-methoxy-acetoacetate (8.77 g, 60.7 mmol) in dry THF
(100 mL). The reaction is stirred overnight at room temperature. Water
(30 mL) is added and the solution concentrated (.about.30 mL). The
resulting mixture is extracted with ether (2.times.50 mL). The aqueous
portion is acidified with concentrated hydrochloric acid and extracted
with CH.sub.2Cl.sub.2 (4.times.100 mL). The combined organic extracts are
dried over Na.sub.2SO.sub.4 and the solvent removed under reduced
pressure to yield the title compound as a light brown oil that solidifies
upon standing.
9. 2-Methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]napthyridin-4-o-
l
##STR00032##
[0272]4-Hydroxy-2-methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]na-
pthyridine-3-carboxylic acid methyl ester (200 mg, 0.508 mmol) is
dissolved in 12 M HCl (20 mL) and heated at 110.degree. C. for 6 hours.
The reaction mixture is poured onto ice (100 g) and extracted with
CH.sub.2Cl.sub.2 (4.times.150 mL). The combined organic extracts are
dried over Na.sub.2SO.sub.4 and the solvent removed under reduced
pressure. The crude product is purified by silica gel preparatory TLC
eluting with hexanes/acetone (3:1) yielding the title compound as a white
solid.
10. 4-Chloro-2-methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]napth-
yridine
##STR00033##
[0274]2-Methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]napthyridin--
4-ol (191 mg, 0.569 mmol) is dissolved in a solution of chloroform (15
mL), POCl.sub.3 (0.212 mL, 2.28 mmol) and 2,6-lutidine (0.256 mL, 2.28
mmol). The reaction is heated at reflux overnight. The mixture is
concentrated under reduced pressure. The resulting residue is dissolved
in EtOAc (50 mL) and extracted with water (50 mL), saturated NaHCO.sub.3
(aq) (50 mL) and brine (50 mL). The organic extract is dried over
Na.sub.2SO.sub.4 and the solvent removed under reduced pressure. The
crude product is purified by column chromatography on silica gel eluting
with hexanes/EtOAc (1:1) to yield the title compound as a white solid.
11. 2-Methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]napthyridin-4--
yl]-(4-trifluoromethylphenyl)-amine
##STR00034##
[0276]4-Chloro-2-methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]nap-
thyridine (25 mg, 0.0708 mmol) is dissolved in a solution of isopropyl
alcohol (2 mL) and 4-trifluoromethyl-aniline (25 mg, 0.155 mmol). The
mixture is heated overnight at 60.degree. C. The solution is concentrated
under reduced pressure. The title compound is isolated as a light yellow
solid after silica gel preparatory TLC eluting with hexanes/acetone
(2:1). Mass Spec 479 (M+1).
[0277]B. Using a similar procedure,
2-methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]napthyridin-4-yl--
(4-t-butylphenyl)-amine (Mass spec 467.2) is prepared:
##STR00035##
[0278]C. 2-Methoxymethyl-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluo-
romethyl)pyridin-2-yl]-[1,8]naphthyridin-4-amine is prepared according to
the procedure shown in Scheme 2, as follows:
##STR00036##
[0279]To a de-gassed mixture of
4-chloro-2-methoxymethyl-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyr-
idine (1 mmol), cesium carbonate (2 mmol), 2-amino-trifluoromethyl
pyridine (1 mmol) in dioxane (10 mL) under nitrogen, add Pd.sub.2
dba.sub.3 (0.05 mmol) and xantphos (0.05 mol). Stir the mixture at
90.degree. C. overnight, concentrate, and extract with EtOAc. Dry over
Na.sub.2SO.sub.4 and concentrate under vacuum. Purify by column
chromatography eluting with dichloromethane/methanol/ammonium hydroxide
mixture to give
2-methoxymethyl-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl-
)pyridin-2-yl]-[1,8]naphthyridin-4-amine. MS 480 (M+1). .sup.1H NMR
.delta. (CDCl.sub.3) 8.88 (1H, d), 8.62 (1H, s), 8.18 (1H, d), 8.07 (1H,
s), 7.88 (1H, dd), 7.84 (1H, d), 7.56 (1H, d), 7.54 (1H, d), 7.30 (1H,
d), 4.77 (2H, s), 3.52 (3H, s), 2.63 (1H, br s).
[0280]D. 4-[(4-Trifluoromethylphenyl)amino]-7-(3-trifluoromethylpyridin-2--
yl)-2-methoxymethyl-[1,8]naphthyridine-3-carboxylic acid is prepared
according to the procedure shown in Scheme 3, by the following steps:
1. Methyl 4-chloro-2-methoxymethyl-7-[3-(trifluoromethyl)pyridin-2-yl]-[1,-
8]naphthyridine-3-carboxylate
##STR00037##
[0282]Dissolve
4-hydroxy-2-methoxymethyl-7-(3-trifluoromethylpyridin-2-yl)-[1,8]naphthyr-
idine-3-carboxylic acid methyl ester (500 mg, 1.27 mmol) in a solution of
POCl.sub.3 (0.4 mL), 2,6-lutidine (0.43 mL) and CHCl.sub.3 (25 mL). Heat
the mixture at reflux overnight. Remove the solvent under reduced
pressure. Partition the residue between CH.sub.2Cl.sub.2 and saturated
NaHCO.sub.3 (aq). Extract the aqueous layer twice with CH.sub.2Cl.sub.2
(2.times.100 mL). Dry the combined organic extracts over
Na.sub.2SO.sub.4. Remove the solvent under reduced pressure. Purify the
crude product by preparatory TLC eluting with EtOAc\Hexanes (1:1) to
yield the title compound.
2. Methyl 4-[(4-trifluoromethylphenyl)amino]-7-(3-trifluoromethylpyridin-2-
-yl)-2-methoxymethyl-[1,8]naphthyridine-3-carboxylate
##STR00038##
[0284]Dissolve methyl
4-chloro-2-methoxymethyl-7-[3-(trifluoromethyl)pyridin-2-yl]-[1,8]naphthy-
ridine-3-carboxylate (212 mg, 0.52 mmol) in acetonitrile (5 mL) and add 4
drops 2M HCl (Et.sub.2O). Stir the mixture for 3 hours at room
temperature. Filter off the resulting yellow precipitate to yield the
title compound as its hydrochloride salt. MS 537.20 (M+1). .sup.1H NMR
.delta. (Free base, CDCl.sub.3) 9.91 (1H, s), 8.88 (1H, m), 8.16 (2H, m),
7.67-7.55 (4H, m), 7.12 (1H, d), 6.99 (1H, d), 4.42 (2H, s), 4.02 (3H,
s), 3.95 (3H, s).
3. 4-[(4-Trifluoromethylphenyl)amino]-7-(3-trifluoromethylpyridin-2-yl)-2--
methoxymethyl-[1,8]naphthyridine-3-carboxylic acid
##STR00039##
[0286]Stir a solution of methyl
4-[(4-trifluoromethylphenyl)amino]-7-(3-trifluoromethylpyridin-2-yl)-2-me-
thoxymethyl-[1,8]naphthyridine-3-carboxylate (114 mg, 0.212 mmol),
LiOH.H.sub.2O (45.0 mg, 1.06 mmol), THF (2 mL) and water (0.1 mL) for 18
hours at room temperature. Add water (20 mL) and acidify with acetic
acid. Extract the solution with EtOAc (3.times.25 mL). Wash the combined
organic extracts with brine and dry over Na.sub.2SO.sub.4. Remove the
solvent under reduced pressure to yield the title compound. MS 523.18
(M+1). .sup.1H NMR .delta. (CDCl.sub.3) 11.50 (1H, br s), 8.89 (1H, s),
8.19 (2H, d), 7.88 (1H, dd), 7.67 (2H, m), 7.59 (1H, dd), 7.51 (2H, d),
7.22 (1H, br s), 5.30 (2H, s), 3.65 (3H, s).
[0287]E. 4-(tert-Butyl-phenyl)-[2-methoxy-7-(3-trifluoromethyl-pyridin-2-y-
l)-[1,8]naphthyridin-4-yl]-amine is prepared according to the procedure
shown in Scheme 4, as follows:
1. 6-Amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid
##STR00040##
[0289]Heat a mixture of
6-amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carbonitrile (5 g) in
concentrated hydrochloric acid at 100.degree. C. for 12 hours. Cool the
mixture and evaporate to dryness to give the hydrochloride salt of the
title compound.
2. 6-Amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid methyl
ester
##STR00041##
[0291]Saturate a solution of
6-amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid (5 g) in
methanol (100 ml) with hydrogen chloride gas. Heat the mixture at reflux
for 4 days and evaporate to dryness. Partition the mixture between ethyl
acetate and saturated sodium bicarbonate solution. Separate the layers
and extract the aqueous layer with further ethyl acetate. Wash the
combined organic extracts with brine, dry (MgSO.sub.4) and evaporate to
give the title compound.
3. 4-Hydroxy-7-(3-trifluoromethyl-pyridin-2-yl)-1H-[1,8]naphthyridin-2-one
##STR00042##
[0293]Heat a solution of
6-amino-3'-trifluoromethyl-[2,2']bipyridinyl-5-carboxylic acid methyl
ester (1.0 mmol) acetic anhydride (2 mL) in pyridine (2 mL) at 90.degree.
C. for 8 hours. Cool the mixture and evaporate to dryness. Add saturated
aqueous sodium bicarbonate (30 mL) and extract with ethyl acetate. Wash
the combined organic extracts with brine, dry and evaporate. Dissolve the
solid in THF (4 mL) and add drop wise to a solution of potassium
bis(trimethylsilyl)amide (600 mg, 3.0 mmol) in toluene (6 mL) at
-78.degree. C. Allow the reaction to return to room temperature
overnight. Add water (10 mL) and extract with ethyl acetate. Acidify the
aqueous layer with hydrochloric acid and collect the precipitate by
filtration. Air-dry to give the title compound.
4. 2,4-Dichloro-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyridine
##STR00043##
[0295]Reflux
4-hydroxy-7-(3-trifluoromethyl-pyridin-2-yl)-1H-[1,8]naphthyridin-2-one
(1.2 g) for 18 hours in POCl.sub.3 (5 mL). Evaporate the solvent,
carefully neutralize with saturated NaHCO.sub.3 and extract with EtOAc.
Dry over Na.sub.2SO.sub.4 and concentrate under vacuum to obtain the
title compound.
5. 4-Chloro-2-methoxy-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyridin-
e
##STR00044##
[0297]Add sodium methoxide (4M, 1.0 mL, 4.0 mmol) to a solution of
2,4-dichloro-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyridine (1.2
g, 3.5 mmol) in THF (30 mL). Stir at room temperature overnight, add
water (25 mL) and extract with ethyl acetate. Wash the combined organic
extracts with brine, dry (MgSO.sub.4) and evaporate. Purify the residue
by flash chromatography (elute with 1:2 hexane:ether) to give the title
compound.
6. 4-tert-Butyl-phenyl)-[2-methoxy-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8-
]naphthyridin-4-yl]-amine
##STR00045##
[0299]Heat a mixture of
4-chloro-2-methoxy-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyridine
(500 mg, 1.47 mmol), 4-tert-butylaniline (240 mg, 1.6 mmol), palladium
acetate (33 mg, 0.15 mmol), 2-(dicyclohexylphosphino)biphenyl (53 mg,
0.15 mmol) and potassium phosphate (0.5 M, 9 mL, 4.5 mmol) in dioxane (20
mL) at 100.degree. C. for 16 hours. Cool the mixture and partition
between ethyl acetate and water. Separate the layers and extract the
aqueous layer with further ethyl acetate. Wash the combined organic
extracts with brine, dry (MgSO.sub.4) and evaporate. Triturate the
residue with ether to give the title compound as the hydrochloride salt.
MS 453 (M+1). .sup.1H NMR .delta. (DMSO) 9.07 (1H, s), 8.95 (1H, d), 8.86
(1H, d), 8.38 (1H, d), 7.77 (1H, m), 7.66 (1H, d), 7.44 (2H, d), 7.29
(2H, d), 6.27 (1H, s), 3.88 (3H, s), 1.30 (9H, s).
[0300]F. (4-Trifluoromethyl-phenyl)-[7-(3-trifluoromethyl-pyridin-2-yl)-[1-
,8]naphthyridin-4-yl-amine is prepared according to the procedure shown in
Scheme 5, as follows:
1. 4-(4-Trifluoromethyl-phenylamino)-7-(3-trifluoromethyl-pyridin-2-yl)-[1-
,8]naphthyridin-2-ol
##STR00046##
[0302]Heat 4-chloro-2-methoxy-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naph-
thyridine (600 mg, 1.8 mmol), 4-trifluoromethylaniline (322 mg, 2.0 mmol)
and 2M hydrochloric acid in ether (1 mL, 2.0 mmol) in isopropanol (15 mL)
at 80.degree. C. for 16 hours. Cool the mixture and collect the
precipitate by filtration. Partition the solid between ethyl acetate and
saturated sodium bicarbonate solution. Separate the layers and extract
the aqueous layer with further ethyl acetate. Wash the combined organic
extracts with brine, dry (MgSO.sub.4) and evaporate to give the title
compound.
2. 2-Chloro-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyridin-4-yl]-(4--
trifluoromethyl-phenyl)-amine
##STR00047##
[0304]Reflux
4-(4-trifluoromethyl-phenylamino)-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8-
]naphthyridin-2-ol (233 mg) for 2 hours in POCl.sub.3 (2 mL). Evaporate
the solvent, carefully neutralize with saturated NaHCO.sub.3, and extract
with EtOAc. Dry over Na.sub.2SO.sub.4, concentrate under vacuum to obtain
the title compound.
3. (4-Trifluoromethyl-phenyl)-[7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]nap-
hthyridin-4-yl-amine
##STR00048##
[0306]Hydrogenate, at 50 psi, a mixture of 10% Pd--C (10 mg) and
2-chloro-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyridin-4-yl]-(4-tr-
ifluoromethyl-phenyl)-amine (40 mg) in 95% EtOH (10 mL). Filter through a
celite pad and concentrate the filtrate. Purify the residue by
preparative TLC (elute with 2:1 ethyl acetate:hexane) to give the title
compound. MS 435 (M+1). .sup.1H NMR .delta. (CDCl.sub.3) 8.98 (1H, d),
8.74 (1H, s), 8.62 (1H, m), 8.18 (1H, d), 7.78 (1H, d), 7.62 (2H, d),
7.50 (3H, m), 6.80 (1H, m).
[0307]G. 7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-
-2-yl]-1,8-naphthyridin-4-amine is prepared according to the procedure
shown in Scheme 5, as follows:
1. 2-Methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyr-
idin-2-yl]-1,8-naphthyridin-4-amine
##STR00049##
[0309]To a de-gassed mixture of
4-chloro-2-methoxy-7-(3-trifluoromethyl-pyridin-2-yl)-[1,8]naphthyridine
(1 mmol), cesium carbonate (2 mmol), 2-aminotrifluoromethylpyridine (1
mmol) in dioxane (10 mL) under nitrogen, add Pd.sub.2 dba.sub.3 (0.05
mmol) and xantphos (0.05 mol). Stir the mixture at 90.degree. C.
overnight, concentrate, and extract with EtOAc. Dry over Na.sub.2SO.sub.4
and concentrate under vacuum. Purify by column chromatography eluting
with dichloromethane/methanol/ammonium hydroxide mixture to give the
title compound.
2. 7-[3-(Trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyridin-2-yl-
]amino}-1,8-naphthyridin-2-ol
##STR00050##
[0311]Heat 2-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluorome-
thyl)pyridin-2-yl]-[1,8]naphthyridin-4-amine (128 mg), 1M hydrochloric
acid in ether (0.25 mL) and isopropanol at 80.degree. C. overnight. Cool
and collect the precipitate by filtration to give the hydrochloride salt
of the title compound.
3. 2-Chloro-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyri-
din-2-yl]-1,8-naphthyridin-4-amine
##STR00051##
[0313]Heat 7-[3-(trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyri-
din-2-yl]amino}-[1,8]naphthyridin-2-ol (112 mg) and phosphorus oxychloride
(1 mL) at reflux for 1 hour. Evaporate to dryness, partition between
ethyl acetate and saturated aqueous NaHCO.sub.3 and extract with EtOAc.
Dry the combined organics over Na.sub.2SO.sub.4, concentrate under vacuum
to obtain the title compound.
4. 7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-2-yl]-
-1,8-naphthyridin-4-amine
##STR00052##
[0314]Stir a mixture of
2-chloro-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridi-
n-2-yl]-[1,8]naphthyridin-4-amine (40 mg), ammonium formate (31 mg), 10%
palladium on carbon (10 mg) in methanol (2 mL) at 50.degree. C. for 2
hours. Cool, filter through Celite and evaporate to dryness. Purify by
preparative thin layer chromatography, eluting with
dichloromethane/methanol/ammonium hydroxide mixture to give the title
compound. MS 436 (M+1). .sup.1H NMR .delta. (CDCl.sub.3) 8.99 (1H, s),
8.84 (1H, d), 8.63 (1H, d), 8.61 (1H, s), 8.32 (1H, brs), 8.14 (1H, d),
8.05 (1H, brs), 7.79-7.85 (2H, m), 7.51 (1H, dd), 7.22 (1H, d).
[0315]H. 4-[(4-Trifluoromethylphenyl)amino]-7-(3-trifluoromethylpyridin-2--
yl)-2-(methoxymethyl)-1,8-naphthyridine-3-carboxylic acid is prepared
according to the procedure shown in Scheme 6, as follows:
1. 7-[3-(Trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyridin-2-yl-
]amino}-1,8-naphthyridine-2-carbonitrile
##STR00053##
[0317]In a sealed tube, bubble argon through a solution of
2-chloro-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridi-
n-2-yl]-1,8-naphthyridin-4-amine (360 mg, 0.766 mmol), ZnCN.sub.2 (63 mg,
0.536 mmol), DMF (10 mL) and water (0.1 mL). Add Pd.sub.2 dba.sub.3 (21
mg, 0.023 mmol) and DPPF (25 mg, 0.046 mmol) to the degassed solution and
heat the mixture at 120.degree. C. for one hour. Cool the mixture and add
EtOAc (100 mL). Extract the mixture with 1N NaOH (3.times.100 mL). Dry
the organic layer over Na.sub.2SO.sub.4 and remove the solvent under
reduced pressure. Triturate the resulting solid with Et.sub.2O to yield
the title compound as an orange solid. MS 461.02 (M+1). .sup.1H NMR
.delta. (CDCl.sub.3) 8.90 (1H, d), 8.76 (1H, s), 8.73 (1H, s), 8.59 (1H,
d), 8.20 (1H, dd), 8.04 (1H, d), 7.96 (1H, dd), 7.91 (1H, m), 7.59 (1H,
dd), 7.22 (1H, d).
2. 7-[3-(Trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyridin-2-yl-
]amino}-1,8-naphthyridine-2-carboxamide
##STR00054##
[0319]Dissolve
7-[3-(trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyridin-2-yl]a-
mino}-1,8-naphthyridine-2-carbonitrile (25 g, 0.054 mmol) in concentrated
H.sub.2SO.sub.4 (2 mL) and stir the mixture overnight at ambient
temperature. Pour the mixture onto ice and adjust the pH to about 7-8.
Filter off the resulting precipitate to yield the title compound as an
off-white solid. MS 479.02 (M+1). .sup.1H NMR .delta. (CD.sub.3OD) 9.32
(1H, s), 9.10 (1H, d), 8.97 (1H, d), 8.71 (1H, s), 8.41 (1H, d), 8.05
(1H, d), 7.95 (1H, d), 7.82 (1H, m), 8.90 (1H, s), 7.44.
3. 7-[3-(Trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyridin-2-yl-
]amino}-1,8-naphthyridine-2-carboxylic acid
##STR00055##
[0321]Dissolve
7-[3-(trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyridin-2-yl]a-
mino}-1,8-naphthyridine-2-carboxamide (25 mg, 0.054 mmol) in 12M HCl (3
mL) and heat at 85.degree. C. overnight. Pour onto ice and adjust the pH
to about 4. Extract with EtOAc (3.times.100 mL). Dry the combined organic
extracts over Na.sub.2SO.sub.4 and remove the solvent under reduced
pressure. Purify the crude residue by preparatory TLC eluting with
CH.sub.2Cl.sub.2/MeOH/AcOH (90:10:1) to yield the title compound. MS
480.00 (M+1). .sup.1H NMR .delta. (CD.sub.3OD) 9.58 (1H, s), 9.20 (1H,
m), 8.95 (1H, m), 8.80 (1H, s), 8.38 (1H, m), 8.13 (1H, d), 8.00 (1H, m),
7.75 (1H, m), 7.55 (1H, d).
Example 2
Preparation of Additional Representative Substituted Quinolin-4-ylamine
Analogues
[0322]A. (4-tert-Butyl-phenyl)-[7-(2-trifluoromethyl-phenyl)-quinolin-4-yl-
]-amine is prepared by the following steps:
1. 7-(2-Trifluoromethyl-phenyl)-quinolin-4-ol
##STR00056##
[0324]Combine 7-chloroquinolin-4-ol (1000 mg, 5.55 mmol,)
2-(trifluoromethyl)phenylboronic acid (1583 mg, 8.33 mmol) and toluene
(50 mL), and bubble nitrogen into the solution for 10 minutes. Add
palladium acetate (25 mg, 0.11 mmol), 2-(dicyclohexylphosphino)biphenyl
(78 mg, 0.22 mmol), and K.sub.3PO.sub.4 (2353 mg, 11.1 mmol) and heat at
90.degree. C. for 16 hours. Let cool, add water (25 mL) and EtOAc (50
mL), and remove any insoluble material by filtration. Separate the EtOAc
layer, and extract the aqueous layer twice with EtOAc (25 mL each).
Combine the EtOAc extracts, dry (Na.sub.2SO.sub.4), and evaporate. Purify
by silica gel chromatography (94% CH.sub.2Cl.sub.2/5% MeOH/1% NH.sub.4OH)
to provide 7-(2-trifluoromethyl-phenyl)-quinolin-4-ol as a white solid.
2. 4-Chloro-7-(2-trifluoromethyl-phenyl)-quinoline
##STR00057##
[0326]Heat a mixture of 7-(2-trifluoromethyl-phenyl)-quinolin-4-ol (50 mg,
0.17 mmol) in POCl.sub.3 (10 mL) at 90.degree. C. for 16 hours. Evaporate
the POCl.sub.3, and add ice (100 g) followed by careful addition of
saturated NaHCO.sub.3. Extract with EtOAc, dry (Na.sub.2SO.sub.4), and
evaporate to provide 4-chloro-7-(2-trifluoromethyl-phenyl)-quinoline as a
tan solid.
3. (4-tert-Butyl-phenyl)-[7-(2-trifluoromethyl-phenyl)-quinolin-4-yl]-amin-
e
##STR00058##
[0328]Heat a mixture of 4-chloro-7-(2-trifluoromethyl-phenyl)-quinoline
(42 mg, 0.14 mmol) and 4-(tert-butyl)aniline (41 mg, 0.29 mmol) in
2-propanol (10 mL) at reflux for 3 hours. Evaporate the mixture, add 1M
NaOH (10 mL), extract twice with EtOAc (10 mL each), dry
(Na.sub.2SO.sub.4), and evaporate to provide the crude product. Purify by
silica gel chromatography, eluting with 75% hexane-EtOAc to provide
(4-tert-butyl-phenyl)-[7-(2-trifluoromethyl-phenyl)-quinolin-4-yl]-amine
as a white solid. Mass spec. 420.2.
[0329]B. 6-Methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,3-b]-
pyrazin-8-yl]-(4-trilfluoromethyl-phenyl)-amine is prepared by the
following steps:
1. 2-(1,2-Dimethoxy-ethylidene)-3-oxo-pentanedioic acid dimethyl ester
##STR00059##
[0331]Dimethyl 1,3-acetonedicarboxylate (20.0 g, 115 mmol) is dissolved in
a solution of 1,1,1,2-tetramethoxy-ethane (23.8 g, 158 mmol) and acetic
anhydride (420 mL) and the solution is heated to reflux for 4 hours. The
mixture is concentrated under reduced pressure. Toluene (200 mL) is added
and the solvent removed under reduced pressure to yield the title
compound.
2. 4,6-Dihydroxy-2-methoxymethyl-nicotinic acid methyl ester
##STR00060##
[0333]2-(1,2-Dimethoxy-ethylidene)-3-oxo-pentanedioic acid dimethyl ester
(29.8 g, 115 mmol) is dissolved in a solution of EtOH (250 mL), water
(250 mL) and concentrated NH.sub.4OH(aq) (30 mL). The mixture is heated
to 60.degree. C. for 5 hours. The reaction mixture is cooled to room
temperature and the EtOH removed under reduced pressure. The remaining
aqueous solution is cooled in an ice bath and acidified with concentrated
hydrochloric acid, at which time a white precipitate appeared. The
precipitate is collected and dried in a vacuum oven to yield the title
compound.
3. 4,6-Dihydroxy-2-methoxymethyl-5-nitro-nicotinic acid methyl ester
##STR00061##
[0335]4,6-Dihydroxy-2-methoxymethyl-nicotinic acid methyl ester (15.9 g,
74.75 mmol) is dissolved in AcOH (60 mL) and cooled to 0.degree. C. in an
ice bath. Nitric acid (70%, 4.73 mL) is added dropwise. The resulting
solution is stirred at room temperature overnight. Water (200 mL) is
added to the mixture and a white precipitate forms. The precipitate is
collected and dried in a vacuum oven to afford the title compound as a
white solid.
4. 6-Methoxymethyl-3-nitro-pyridine-2,4-diol
##STR00062##
[0337]4,6-Dihydroxy-2-methoxymethyl-5-nitro-nicotinic acid methyl ester
(2.00 g, 7.75 mmol) is placed in concentrated hydrochloric acid (100 mL)
and heated in a bomb at 120.degree. C. overnight. The reaction mixture is
cooled in an ice bath and poured onto ice (200 g). A white precipitate
formed. The precipitate is collected and dried in a vacuum oven to afford
the title compound.
5. 2,4-Dichloro-6-methoxymethyl-3-nitro-pyridine
##STR00063##
[0339]6-Methoxymethyl-3-nitro-pyridine-2,4-diol (725 mg, 3.63 mmol) is
added to a solution of POCl.sub.3 (15 mL) at 0.degree. C. The mixture is
warmed to room temperature followed by heating at reflux for 5 hours.
Excess POCl.sub.3 is removed under reduced pressure to yield a light
brown oil. The crude oil is dissolved in CH.sub.2Cl.sub.2 (100 mL) and
extracted with water (100 mL), NaHCO.sub.3 (100 mL), and brine (100 mL).
The organic extract is dried over Na.sub.2SO.sub.4 and the solvent
removed under reduced pressure. The crude product is chromatographed on
silica gel eluting with hexanes/EtOAc (4:1) to yield the title compound
as a light yellow oil.
6. 6-Methoxymethyl-3-nitro-pyridine-2,4-diamine
##STR00064##
[0341]A solution of saturated ammonia in methanol (20 mL) is added to
2,4-dichloro-6-methoxymethyl-3-nitro-pyridine (620 mg, 2.61 mmol). The
mixture is stirred for 1 hour at room temperature. A white precipitate
forms and is collected. The precipitate is dried in a vacuum oven to
afford the title compound as a white solid.
7. 6-Methoxymethyl-2,3,4-triamino-pyridine
##STR00065##
[0343]6-Methoxymethyl-3-nitro-pyridine-2,4-diamine (455 mg, 2.29 mmol) is
dissolved in EtOH (50 mL) and 10% Pd/C (50 mg) is added. The mixture is
hydrogenated at 50 psi for 2 hours. The reaction mixture is filtered
through Celite and the Celite bed washed with EtOH (25 mL). The solvent
is removed under reduced pressure to yield the title compound as an
off-white solid.
8. 6-Methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,3-b]pyrazi-
n-8-ylamine
##STR00066##
[0345]6-Methoxymethyl-2,3,4-triamino-pyridine (353 mg, 2.10 mmol),
2-bromo-1-(3-trifluoromethyl-pyridin-2-yl)-ethanone hydrobromide (771 mg,
2.21 mmol; synthesis described in Example 2E, below), and NaHCO.sub.3
(554 mg, 6.59 mmol) are dissolved into a solution of dioxane (20 mL) and
water (20 mL). The reaction mixture is stirred 1 hour at room temperature
and 3 hours at 100.degree. C. The mixture is cooled and filtered through
Celite. The Celite bed is washed with EtOAc (20 mL). The aqueous mixture
is extracted with EtOAc (4.times.100 mL). The combined organic extracts
are washed with brine and dried over Na.sub.2SO.sub.4. The solvent is
removed under reduced pressure and the crude product purified by column
chromatography on silica gel eluting with acetone/hexanes (1:1) to yield
the title compound as a white solid.
9. 6-Methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,3-b]pyrazi-
n-8-ol
##STR00067##
[0347]6-Methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,3-b]pyr-
azin-8-ylamine (252 mg, 0.751 mmol) is dissolved in a solution of acetic
acid (2 mL) and water (5 mL). The mixture is heated to 50.degree. C. and
sodium nitrite (362 mg, 5.26 mmol) is added in portions over 1 hour. The
solution is warmed to 70.degree. C. and stirred overnight. Water (20 mL)
is added and the aqueous mixture is extracted with EtOAc (4.times.50 mL).
The combined organic extracts are washed with brine and dried over
Na.sub.2SO.sub.4. The solvent is removed under reduced pressure. The
crude product is chromatographed on silica gel eluting with
hexanes/acetone (1:1) to afford the title compound as a white solid.
10. 8-Chloro-6-Methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,-
3-b]pyrazine
##STR00068##
[0349]6-Methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,3-b]pyr-
azin-8-ol (146 mg, 0.436 mmol) is dissolved in a solution of CHCl.sub.3
(20 mL), POCl.sub.3 (0.12 ml, 1.31 mmol) and 2,6-lutidine (0.2 mL, 1.31
mmol). The mixture is heated at reflux overnight. The reaction is
concentrated under reduced pressure. EtOAc (30 mL) is added and the
mixture is extracted with NaHCO.sub.3 (aq) (30 mL) and brine (30 mL). The
organic extract is dried over Na.sub.2SO.sub.4 and the solvent removed
under reduced pressure. The crude product is purified by silica gel
preparatory TLC eluting with hexanes/EtOAc (1:1) to yield the title
compound as a light yellow oil that solidifies upon standing.
11. 6-Methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,3-b]pyraz-
in-8-yl]-(4-trilfluoromethyl-phenyl)-amine
##STR00069##
[0351]To a solution of acetonitrile (2.5 mL) and 4-trifluoromethylaniline
(42 mg, 0.263 mmol) is added
8-chloro-(6-methoxymethyl-3-(3-trifluoromethyl-pyridin-2-yl)-pyrido-[2,3--
b]pyrazine (62 mg, 0.175 mmol) in acetonitrile (1 mL). The mixture is
heated at 80.degree. C. overnight. The solvent is removed under reduced
pressure and the crude reaction mixture purified by silica gel
preparatory TLC eluting with hexanes/acetone (2:1) to afford the title
compound as a light yellow solid.
[0352]C. 7-[3-(Trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-
-2-yl]-1,5-naphthyridin-4-amine is prepared according to the procedure
shown in Scheme 7, as follows:
1. 5-Amino-3-trifluoromethyl-[2,3']bipyridinyl-6'-carbonitrile
##STR00070##
[0354]Heat a solution of
6'-chloro-3-trifluoromethyl-[2,3']bipyridinyl-5'-ylamine (25 g, 0.091
mol; prepared essentially as described in PCT International Application
Publication Number WO 03/062209, published on Jul. 31, 2003), zinc
cyanide (6.75 g, 0.058 mol), pd.sub.2(dba).sub.3 (2.63 g, 2.86 mmol),
DPPF (3.16 g, 5.72 mmol) in DMF (250 mL) and water (2.5 mL), under a
nitrogen atmosphere, at 120.degree. C. for 1 hour. Cool the reaction to
0.degree. C. and add a solution of saturated ammonium chloride (200 ml),
water (200 mL) and concentrated ammonium hydroxide (50 mL). After
stirring at 0.degree. C. for 1 hour, filter the yellow precipitate, and
wash with water (200 mL) and a 1:1 mixture of ether-hexane (200 mL). Dry
the solid in air and then in a vacuum oven to give the title compound.
2. 5-Amino-3-trifluoromethyl-[2,3']bipyridinyl-6'-carboxylic acid
##STR00071##
[0356]Dissolve 5-amino-3-trifluoromethyl-[2,3']bipyridinyl-6'-carbonitrile
(5 g, 18.9 mmol) in 12M HCl (100 mL) and heat at 100.degree. C.
overnight. Remove the aqueous acid under reduced pressure to yield the
title compound as its hydrochloride salt.
3. Ethyl 5'-amino-3-trifluoromethyl-[2,3']bipyridine-6'-carboxylate
##STR00072##
[0358]Saturate a solution of
5-amino-3-trifluoromethyl-[2,3']bipyridinyl-6'-carboxylic acid (5 g) in
ethanol (100 ml) with hydrogen chloride gas. Heat the mixture at reflux
for 4 days and evaporate to dryness. Partition the mixture between ethyl
acetate and saturated sodium bicarbonate solution. Separate the layers
and extract the aqueous layer with further ethyl acetate. Wash the
combined organic extracts with brine, dry (MgSO.sub.4) and evaporate to
give the title compound.
4. 7-[3-(Trifluoromethyl)pyridin-2-yl]-[1,5]naphthyridine-2,4-diol
##STR00073##
[0360]Heat a solution of ethyl
5'-amino-3-trifluoromethyl-[2,3']bipyridine-6'-carboxylate (10 mmol) and
acetic anhydride (15 mL) in pyridine (15 mL) at 90.degree. C. for 8
hours. Cool the mixture and evaporate to dryness. Add saturated aqueous
sodium bicarbonate (30 mL) and extract with ethyl acetate. Wash the
combined organic extracts with brine, dry and evaporate. Dissolve the
solid in THF (30 mL) and add drop wise to a solution of potassium
bis(trimethylsilyl)amide (6 g, 30 mmol) in toluene (60 mL) at -78.degree.
C. Allow the reaction to return to room temperature overnight. Add water
(100 mL) and extract with ethyl acetate. Acidify the aqueous layer with
hydrochloric acid and collect the precipitate by filtration. Air-dry to
give the title compound.
5. 2,4-Dichloro-7-[3-(trifluoromethyl)pyridin-2-yl]-[1,5]naphthyridine
##STR00074##
[0362]Reflux
7-[3-(trifluoromethyl)pyridin-2-yl]-[1,5]naphthyridine-2,4-diol (1 g) for
18 hours in POCl.sub.3 (5 mL). Evaporate the solvent, then carefully
neutralize with saturated NaHCO.sub.3 and extract with EtOAc. Dry over
Na.sub.2SO.sub.4, concentrate under vacuum to obtain the title compound.
6. 4-Chloro-2-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]-[1,5]naphthyridi-
ne
##STR00075##
[0364]Add sodium methoxide (4M, 0.45 mL, 1.8 mmol) to a solution of
2,4-dichloro-7-[3-(trifluoromethyl)pyridin-2-yl]-1,5-naphthyridine (575
mg, 1.6 mmol) in THF (10 mL). Stir at room temperature for 1 hour, add
water (15 mL) and extract with ethyl acetate. Wash the combined organic
extracts with brine, dry (MgSO.sub.4) and evaporate. Purify the residue
by flash chromatography (elute with 1:2 hexane:ether) to give the title
compound.
7. 2-Methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyr-
idin-2-yl]-[1,5]naphthyridin-4-amine
##STR00076##
[0366]To a de-gassed mixture of
4-chloro-2-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]-[1,5]naphthyridine
(1 mmol), cesium carbonate (2 mmol), 2-amino-trifluoromethylpyridine (1
mmol) in dioxane (10 mL) under nitrogen, add Pd.sub.2 dba.sub.3 (46 mg)
and xantphos (29 mg). Stir the mixture at 100.degree. C. for 3 hours,
cool, add water (10 mL) and extract with EtOAc. Dry the combined extracts
over Na.sub.2SO.sub.4, concentrate under vacuum. Purify by chromatography
eluting with dichloromethane/methanol/ammonium hydroxide mixture to give
the title compound. MS 435.98 (M+1). .sup.1H NMR .delta. (CDCl.sub.3)
8.95 (1H, d), 8.90 (1H, s), 8.58 (1H, s), 8.38 (1H, d), 8.30 (1H, s),
8.19 (1H, d), 8.06 (1H, s), 7.88 (1H, d), 7.55 (1H, m), 7.05 (1H, s),
4.16 (3H, s).
8. 7-[3-(Trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyridin-2-yl-
]amino}-[1,5]naphthyridin-2-ol
##STR00077##
[0368]Heat a solution of
2-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyrid-
in-2-yl]-[1,5]naphthyridin-4-amine (300 mg) in 33% hydrogen bromide in
acetic acid (10 mL) at 100.degree. C. for 18 hours. Evaporate to dryness,
add saturated aqueous sodium bicarbonate (10 mL) and extract with EtOAc.
Dry over Na.sub.2SO.sub.4, and concentrate under vacuum.
9. 2-Chloro-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyri-
din-2-yl]-[1,5]naphthyridin-4-amine
##STR00078##
[0370]Heat 7-[3-(trifluoromethyl)pyridin-2-yl]-4-{[5-(trifluoromethyl)pyri-
din-2-yl]amino}-[1,5]naphthyridin-2-ol (190 mg) and phosphorus oxychloride
(3 mL) at reflux for 30 minutes. Evaporate to dryness, partition between
ethyl acetate and saturated aqueous NaHCO.sub.3 and extract with EtOAc.
Wash the combined extracts with brine and dry over Na.sub.2SO.sub.4,
concentrate under vacuum to obtain the title compound. MS 469.93 (M+1).
.sup.1H NMR .delta. (CDCl.sub.3) 9.04 (1H, s), 8.85 (1H, d), 8.60 (1H,
s), 8.3-8.36 (2H, m), 8.18 (1H, d), 7.90-7.98 (2H, m), 7.58 (1H, m). 10.
7-[3-(Trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-2-yl]-[-
1,5]naphthyridin-4-amine
##STR00079##
[0371]Stir a mixture of
2-chloro-7-[3-(trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridi-
n-2-yl]-[1,5]naphthyridin-4-amine (94 mg), ammonium formate (126 mg), 10%
palladium on carbon (25 mg) in methanol (10 mL) at 50.degree. C. for 2
hours. Cool, filter through Celite and evaporate to dryness. Purify by
preparative thin layer chromatography, eluting with
dichloromethane/methanol/ammonium hydroxide mixture to give the title
compound. MS 436 (M+1). .sup.1H NMR .delta. (CDCl.sub.3) 8.95-8.93 (2H,
m), 8.63-8.57 (2H, m), 8.34-8.32 (2H, m), 8.26 (1H, s), 8.18 (1H, dd),
7.91 (1H, dd), 7.57-7.52 (2H, m).
[0372]D. 7-[3-(Trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-
-2-yl]quinolin-4-amine is prepared according to the procedure shown in
Scheme 8, as follows:
1. 2-p-Tolyl-3-trifluoromethyl-pyridine
##STR00080##
[0374]To a de-gassed mixture of 2-chloro-3-(trifluoromethyl)-pyridine
(70.1 mmol), p-tolylboronic acid (70.6 mmol), and 2M Na.sub.2CO.sub.3
(175.0 mmol), in DME (200 mL) under nitrogen, and add Pd(PPh.sub.3).sub.4
(2.8 mmol). Stir the mixture at 80.degree. C. overnight, concentrate,
extract with EtOAc. Dry over Na.sub.2SO.sub.4, concentrate under vacuum,
and pass through a silica gel pad to give the title compound.
2. 2-(4-Methyl-3-nitro-phenyl)-3-(trifluoromethyl)-pyridine
##STR00081##
[0376]To a solution of 2-p-tolyl-3-trifluoromethyl-pyridine (8.4 mmol) in
H.sub.2SO.sub.4 (6 mL) cautiously add fuming HNO.sub.3 (2 ml). Stir the
mixture for 1 hour at room temperature. Pour the mixture onto ice-water
(30 mL), extract with EtOAc, wash with 1 N NaOH, dry over
Na.sub.2SO.sub.4, and concentrate under vacuum to obtain the title
compound.
3. 2-Nitro-4-(3-trifluoromethyl-pyridin-2-yl)-benzoic acid
##STR00082##
[0378]To a solution of
2-(4-methyl-3-nitro-phenyl)-3-(trifluoromethyl)-pyridine (7.1 mmol) in a
mixture of pyridine (10 mL) and water (5 ml) add KMnO.sub.4 (25.3 mmol)
portion wise. Stir the mixture for 4 hours at 110.degree. C. then add
another 25.3 mmol of KMnO.sub.4 and 10 ml of water. Stir the mixture at
110.degree. C. overnight. Cool to room temperature, filter through celite
pad. Concentrate the filtrate under vacuum, dilute with water, and wash
the aqueous with EtOAc. Neutralize the aqueous layer with 2 N HCl and
collect the precipitate to give the title compound.
4. 2-Nitro-4-(3-trifluoromethyl-pyridin-2-yl)-benzoic acid methyl ester
##STR00083##
[0380]Saturate a solution of
2-nitro-4-(3-trifluoromethyl-pyridin-2-yl)-benzoic acid (5 g) in methanol
(100 ml) with hydrogen chloride gas. Heat the mixture at reflux for 4
days and evaporate to dryness. Partition the mixture between ethyl
acetate and saturated sodium bicarbonate solution. Separate the layers
and extract the aqueous layer with further ethyl acetate. Wash the
combined organic extracts with brine, dry (MgSO.sub.4) and evaporate to
give the title compound.
5. 2-Amino-4-(3-trifluoromethyl-pyridin-2-yl)-benzoic acid methyl ester
##STR00084##
[0382]Hydrogenate, at 50 psi, a mixture of 10% Pd--C (150 mg) and
2-nitro-4-(3-trifluoromethyl-pyridin-2-yl)-benzoic acid methyl ester (2
g) in 95% EtOH (100 mL). Filter through a celite pad and concentrate the
filtrate to give the title compound.
6. 4-Hydroxy-7-(3-trifluoromethyl-pyridin-2-yl)-1H-quinolin-2-one
##STR00085##
[0384]Heat a solution of
2-amino-4-(3-trifluoromethyl-pyridin-2-yl)-benzoic acid methyl ester (296
mg, 1.0 mmol) and acetic acid (1 mL) in dioxane (2 mL) at 60.degree. C.
for 3 hours. Cool the mixture, add water (1 mL) and evaporate to dryness.
Dissolve the solid in THF (4 mL) and add drop wise to a solution of
potassium bis(trimethylsilyl)amide (600 mg, 3.0 mmol) in toluene (6 mL)
at -78.degree. C. Allow the reaction to return to room temperature
overnight. Add water (10 mL) and extract with ethyl acetate. Acidify the
aqueous layer with hydrochloric acid and collect the precipitate by
filtration. Air-dry to give the title compound.
7. 2,4-Dichloro-7-(3-trifluoromethyl-pyridin-2-yl)-quinoline
##STR00086##
[0386]Reflux
4-hydroxy-7-(3-trifluoromethyl-pyridin-2-yl)-1H-quinolin-2-one (306 mg)
for 18 hours in POCl.sub.3 (5 mL). Evaporate the solvent, then carefully
neutralize with saturated NaHCO.sub.3, and extract with EtOAc. Dry over
Na.sub.2SO.sub.4, concentrate under vacuum to obtain the title compound.
8. 2-Chloro-4-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline
##STR00087##
[0388]Add sodium methoxide (4M, 1.1 mmol) to a solution of
2,4-dichloro-7-(3-trifluoromethyl-pyridin-2-yl)-quinoline (1.0 mmol) in
THF (10 mL). Stir at room temperature for 1 hour, add water (15 mL) and
extract with ethyl acetate. Wash the combined organic extracts with
brine, dry (MgSO.sub.4) and evaporate. Purify the mixture of
2-chloro-4-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline and
4-chloro-2-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline by flash
chromatography (elute with 1:2 hexane:ether) to give the title compound.
9. 4-Methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline
##STR00088##
[0390]Stir a mixture of
2-chloro-4-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline (111 mg),
ammonium formate (190 mg), 10% palladium on carbon (30 mg) in methanol
(10 mL) at room temperature for 2 hours. Cool, filter through Celite and
evaporate to give the title compound.
10. 7-[3-(Trifluoromethyl)pyridin-2-yl]quinolin-4-ol
##STR00089##
[0392]Heat a solution of
4-methoxy-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline (100 mg), in 33%
hydrogen bromide in acetic acid (5 mL) at 100.degree. C. for 18 hours.
Evaporate to dryness to give the hydrobromide salt of the title compound.
11. 4-Chloro-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline
##STR00090##
[0394]Reflux 7-[3-(trifluoromethyl)pyridin-2-yl]quinolin-4-ol (145 mg) for
2 hours in POCl.sub.3 (2 mL). Evaporate the solvent, then carefully
neutralize with saturated NaHCO.sub.3, and extract with EtOAc. Dry over
Na.sub.2SO.sub.4, concentrate under vacuum to obtain the title compound.
12. 7-[3-(Trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-2-yl-
]quinolin-4-amine
##STR00091##
[0396]To a de-gassed mixture of
4-chloro-7-[3-(trifluoromethyl)pyridin-2-yl]quinoline (0.5 mmol), cesium
carbonate (1 mmol), 2-amino-trifluoromethylpyridine (0.5 mmol) in dioxane
(5 mL) under nitrogen add Pd.sub.2 dba.sub.3 (23 mg) and xantphos (15
mg). Stir the mixture at 100.degree. C. for 3 h, cool, add water (8 mL)
and extract with EtOAc. Dry over Na.sub.2SO.sub.4, concentrate under
vacuum. Purify by chromatography eluting with
dichloromethane/methanol/ammonium hydroxide mixture and triturate with
ether/hexane to give the title compound. MS 435 (M+1). .sup.1H NMR
.delta. (CDCl.sub.3) 8.73 (1H, d), 8.56 (1H, s), 8.51 (1H, s), 8.40 (2H,
d), 8.11-8.09 (3H, m), 7.85 (1H, d), 7.67 (1H, d), 7.53 (1H, d), 7.47
(1H, dd).
[0397]E. 3-[3-(Trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-
-2-yl]pyrido[2,3-b]pyrazin-8-amine is prepared as shown in Scheme 9, as
follows:
1. 2-Bromo-1-(3-trifluoromethyl-pyridin-2-yl)-ethanone
##STR00092##
[0399]Dissolve 1-(3-trifluoromethyl-pyridin-2-yl)-ethanone (2.10 g, 11.1
mmol) in HBr (30% by wt in AcOH) (14 mL). Cool the mixture to 0.degree.
C. and add bromine (0.62 mL) drop wise. Allow the resulting solution to
warm to room temperature and stir for 3 hours. Concentrate the reaction
under reduced pressure to yield the title compound as its HBr salt.
2. 3-[3-(trifluoromethyl)pyridin-2-yl]pyrido[2,3-b]pyrazin-8-amine
##STR00093##
[0401]Dissolve 2,3,4-triaminopyridine (2.5 mmol) in water (20 mL). Add
NaHCO.sub.3 (0.63 g, 7.5 mmol), dioxane (10 mL), and
2-bromo-1-(3-trifluoromethyl-pyridin-2-yl)-ethanone hydrobromide (0.5 g)
and stir at 100.degree. C. for 2 hours. Cool the mixture and extract with
EtOAc (4.times.10 mL). Wash the combined organic extracts with brine and
dry over Na.sub.2SO.sub.4. Purify the residue by preparative HPLC to give
the title compound.
3. 3-[3-(Trifluoromethyl)pyridin-2-yl]-N-[5-(trifluoromethyl)pyridin-2-yl]-
pyrido[2,3-b]pyrazin-8-amine
##STR00094##
[0403]To a de-gassed mixture of
3-[3-(trifluoromethyl)pyridin-2-yl]pyrido[2,3-b]pyrazin-8-amine (72 mg,
0.25 mmol), cesium carbonate (162 mg, 0.5 mmol), 2-amino-trifluoromethyl
pyridine (45 mg, 0.25 mmol) in dioxane (5 mL) under nitrogen, add
Pd.sub.2 dba.sub.3 (11 mg) and xantphos (7 mg). Stir the mixture at
100.degree. C. for 3 hours, cool, add water (10 mL) and extract with
EtOAc. Dry over Na.sub.2SO.sub.4, concentrate under vacuum. Purify by
chromatography eluting with dichloromethane/methanol/ammonium hydroxide
mixture to give the title compound. MS 437 (M+1). .sup.1H NMR .delta.
(CDCl.sub.3) 9.42 (1H, s), 9.28 (1H, s), 9.11 (1H, d), 8.95 (1H, d), 8.90
(1H, d), 8.72 (1H, s), 8.25 (1H, d), 7.89 (1H, d), 7.61 (1H, dd), 7.13
(1H, d).
[0404]F. 7-(3-Chloropyridin-2-yl)-N-(5-(trifluoromethyl)pyridin-2-yl)-1,8--
naphthyridin-4-amine
1. tert-Butyl 4-chloropyridin-2-ylcarbamate
##STR00095##
[0406]Dissolve azido(4-chloropyridin-2-yl)methanone (1.5 g, 0.008216
moles, prepared essentially as described by Sundberg and Jiang (1997)
Org. Prep. Proced. Int. 29:117-122) in toluene (20.0 mL) and heat at
55.degree. C. for 2.0 hours. Add t-butanol (1.96 mL, 0.02054 moles) to
the reaction mixture and continue heating at 80.degree. C. for 24 hours.
Cool the mixture and concentrate under reduced pressure to afford a
residue. Dissolve the residue in EtOAc/1.0 N aq. NaOH (50.0 mL each).
Separate the organic layer, extract the aqueous solution with EtOAc
(3.times.20.0 mL), wash the EtOAc with brine, dry (MgSO.sub.4) and
concentrate under reduced pressure to afford a red colored solid. Purify
the crude product by flash column chromatography using 5% EtOAc/hexane to
afford the title product as a white solid.
2. tert-Butyl 4-chloro-3-formylpyridin-2-ylcarbamate
##STR00096##
[0408]Dissolve tert-butyl 4-chloropyridin-2-ylcarbamate (1.95 g, 0.00855
moles) in dry THF (50 mL) and cool to -78.degree. C. under nitrogen
atmosphere. Add dropwise 1.6 M n-BuLi/hexane (12.8 mL, 0.02053 moles)
over a period of 15 minutes while maintaining the reaction temperature
below -70.degree. C. Stir the resulting red orange solution at
-78.degree. C. for 2 hours. Add DMF (3.3 mL, 0.04275 moles) dropwise to
the reaction mixture while maintaining the reaction temperature below
-70.degree. C. Stir further at -78.degree. C. for 2 hours and then quench
the reaction mixture with saturated ammonium chloride (50 mL). Warm the
reaction mixture to room temperature, extract with EtOAc (3.times.50 mL)
and dry with MgSO.sub.4. Filter and concentrate under reduced pressure to
afford a yellow viscous oil. Purify the crude product by flash column
chromatography using 15-20% EtOAc/hexane to afford the title product as a
white solid.
3. 2-Amino-4-chloronicotinaldehyde
##STR00097##
[0410]Dissolve tert-butyl 4-chloro-3-formylpyridin-2-ylcarbamate (1.6 g,
6.2 mmol) in anhydrous CH.sub.2Cl.sub.2 (50 mL) under N.sub.2 atmosphere.
Add dropwise trifluoroacetic acid (2.4 mL, 31.0 mmol) to the reaction
mixture and stir at room temperature overnight. Add saturated aq. sodium
carbonate (50 mL) to the reaction mixture, separate the organic layer,
extract the aq. layer with CH.sub.2Cl.sub.2 (2.times.20 mL) and dry with
MgSO.sub.4. Filter and concentrate under reduced pressure to afford the
title product as a yellow solid.
4. 5-Chloro-2-(3-chloropyridin-2-yl)-[1,8]naphthyridine
##STR00098##
[0412]Dissolve 2-amino-4-chloronicotinaldehyde (312 mg, 2.0 mmol) and
2-acetyl-3-chloropyridine (310 mg, 2.0 mmol) in anhydrous THF (5.0 mL)
and cool it to -20.degree. C. under N.sub.2 atmosphere. Add in portion
t-BuOK (448 mg, 4.0 mmol) to the reaction mixture and stir the mixture at
10.degree. C. for 2 hours. Concentrate the reaction mixture under vacuum,
dilute the residue with water (10 mL), filter the solid, wash the solid
with water and dry under high vacuum to afford the title product as a
yellow solid.
5. 7-(3-Chloropyridin-2-yl)-N-(5-(trifluoromethyl)pyridin-2-yl)-[1,8]napht-
hyridin-4-amine
##STR00099##
[0414]Heat a mixture of
5-chloro-2-(3-chloropyridin-2-yl)-[1,8]naphthyridine (82.5 mg, 0.3 mmol)
and 2-amino-5-trifluoromethylpyridine (97.2 mg, 0.6 mmol) at 180.degree.
C. for 2.0 hours. Cool the mixture, dilute with EtOAc/1.0 N aq. NaOH (5.0
mL each), and separate the organic layer, extract the aq. layer with
EtOAc (2.times.5 mL) and dry the combined organic layers with MgSO.sub.4.
Filter the dried extract and concentrate under vacuum to afford crude
product. Purify by column chromatography using EtOAc to 2% MeOH/EtOAc as
eluents to afford title compound as a yellow solid. .sup.1H NMR (400 MHZ,
DMSO-D.sub.6) .delta. 10.2 (s, 1H), 9.07 (d, 1H, J=1.9 Hz), 8.93 (d, 1H,
J=1.2 Hz), 8.68 (m, 2H), 8.47 (s, 1H), 8.08 (m, 2H), 7.96 (d, 1H, J=2.2
Hz), 7.56 (dd, 1H), 7.46 (d, 1H, J=2.2 Hz). MS=402.22 (M+H).
[0415]G. 7-(3-Methylpyridin-2-yl)-N-(5-(trifluoromethyl)pyrimidin-2-yl)-[1-
,8]naphthyridin-4-amine
1. 5-Chloro-2-(3-methylpyridin-2-yl)-1,8-naphthyridine
##STR00100##
[0417]Dissolve 2-amino-4-chloronicotinaldehyde (156 mg, 1.0 mmol) and
2-acetyl-3-methylpyridine (136 mg, 1.0 mmol) in anhydrous THF (5.0 mL)
and cool it to -20.degree. C. under N.sub.2 atmosphere. Add in portion
t-BuOK (224 mg, 2.0 mmol) to the reaction mixture and stir the mixture at
10.degree. C. for 2 hours. Concentrate the reaction mixture under vacuum,
dilute the residue with water (10 mL), filter the solid, wash the solid
with water and dry under high vacuum to afford the title product as a
yellow colored solid.
2. 7-(3-Methylpyridin-2-yl)-N-(5-(trifluoromethyl)pyrimidin-2-yl)-[1,8]nap-
hthyridin-4-amine
##STR00101##
[0419]Heat a mixture of
5-chloro-2-(3-methylpyridin-2-yl)-[1,8]naphthyridine (51 mg, 0.2 mmol),
2-amino-5-trifluoromethylpyrimidine (42.0 mg, 0.25 mmol), xantphos (11.6
mg, 0.02 mmol), Pd.sub.2(dba).sub.3 (18.3 mg, 0.02 mmol) and
Cs.sub.2CO.sub.3 (130 mg, 0.4 mmol) in dioxane (2.0 mL) at 100.degree. C.
for 20 hours. Cool the mixture, concentrate under vacuum, dilute with
EtOAc/water (5.0 mL each), filter through celite, wash celite with EtOAc
(2.times.5 mL) and dry the combined organic layers with MgSO.sub.4.
Filter the dried extract and concentrate under vacuum to afford the crude
product. Purify by column chromatography using EtOAc as eluent to afford
the title compound as a yellow solid. .sup.1H NMR (400 MHZ, DMSO-D.sub.6)
.delta. 10.92 (s, 1H), 9.0 (m, 3H), 8.92 (d, 1H, J=1.8 Hz), 8.58 (d, 1H,
J=1.0 Hz), 8.12 (m, 2H), 7.80 (d, 1H, J=2.1 Hz), 7.41 (dd, 1H), 2.65 (s,
3H). MS=383.3 (M+H).
[0420]H. 7-(3-Methylpyridin-2-yl)-N-(5-(trifluoromethyl)pyrazin-2-yl)-[1,8-
]naphthyridin-4-amine
##STR00102##
[0421]Heat a mixture of
5-chloro-2-(3-methylpyridin-2-yl)-[1,8]naphthyridine (51 mg, 0.2 mmol),
2-amino-5-trifluoromethylpyrazine (42.0 mg, 0.25 mmol), xantphos (11.6
mg, 0.02 mmol), Pd.sub.2(dba).sub.3 (18.3 mg, 0.02 mmol) and
Cs.sub.2CO.sub.3 (130 mg, 0.4 mmol) in dioxane (2.0 mL) at 100.degree. C.
for 20 hours. Cool the mixture, concentrate under vacuum, dilute with
EtOAc/water (5.0 mL each), filter through celite, wash celite with EtOAc
(2.times.5 mL) and dry the combined organic layers with MgSO.sub.4.
Filter the dried extract and concentrate under vacuum to afford the crude
product. Purify by preparative TLC using 2% MeOH/EtOAc as eluent to
afford the title compound as a yellow solid. .sup.1H NMR (400 MHZ,
DMSO-D.sub.6) .delta. 10.6 (s, 1H), 9.04 (d, 1H, J=2.1 Hz), 9.0 (s, 1H),
8.77 (s, 2H), 8.59 (d, 1H, J=1.6 Hz), 8.4 (s, 1H), 8.20 (d, 1H, J=2.2
Hz), 7.81 (d, 1H, J=1.9 Hz), 7.42 (dd, 1H), 2.65 (s, 3H). MS=383.11
(M+H).
[0422]I. 7-(3-(Trifluoromethyl)pyridin-2-yl)-N-(5-(trifluoromethyl)pyridin-
-2-yl)-1,8-naphthyridin-4-amine
1. 5-Chloro-2-(3-(trifluoromethyl)pyridin-2-yl)-[1,8]naphthyridine
##STR00103##
[0424]Dissolve 2-amino-4-chloronicotinaldehyde (78 mg, 0.5 mmol) and
2-acetyl-3-trifluoromethylpyridine (95 mg, 0.5 mmol) in anhydrous THF
(2.0 mL) and cool it to -20.degree. C. under N.sub.2 atmosphere. Add in
portion t-BuOK (112 mg, 1.0 mmol) to the reaction mixture and stir the
mixture at 10.degree. C. for 2 hours. Concentrate the reaction mixture
under vacuum, dilute the residue with saturated aq. ammonium chloride (10
mL), filter the solid, wash the solid with water and dry under high
vacuum to afford desired product as a cream colored solid.
2. 7-(3-(Trifluoromethyl)pyridin-2-yl)-N-(5-(trifluoromethyl)pyridin-2-yl)-
-[1,8]naphthyridin-4-amine
##STR00104##
[0426]Heat a mixture of
5-chloro-2-(3-(trifluoromethyl)pyridin-2-yl)-[1,8]naphthyridine (62 mg,
0.2 mmol), 2-amino-5-trifluoromethylpyridine (32.4 mg, 0.2 mmol),
xantphos (11.6 mg, 0.02 mmol), Pd.sub.2(dba).sub.3 (18.3 mg, 0.02 mmol)
and Cs.sub.2CO.sub.3 (130 mg, 0.4 mmol) in dioxane (2.0 mL) at
100.degree. C. for 20 hours. Cool the mixture, concentrate under vacuum,
dilute with EtOAc/water (5.0 mL each), filter through celite, wash celite
with EtOAc (2.times.5 mL) and dry combined organic layers with
MgSO.sub.4. Filter the dried extract and concentrate under vacuum to
afford crude product. Purify by preparative TLC using EtOAc as eluent to
afford title compound as a yellow solid. .sup.1H NMR (400 MHZ,
DMSO-D.sub.6) .delta. 10.15 (s, 1H), 9.1 (d, 1H, J=2.2 Hz), 9.0 (d, 1H,
J=1.1 Hz), 8.95 (d, 1H, J=1.2 Hz), 8.68 (s, 1H), 8.50 (d, 1H, J=1.3 Hz),
8.43 (d, 1H, J=2.0 Hz), 8.12 (dd, 1H), 8.0 (d, 1H, J=2.2 Hz), 7.81 (m,
1H), 7.49 (d, 1H, J=2.2 Hz). MS=436.08 (M+H).
Example 3
Additional Representative Substituted Quinolin-4-ylamine Analogues
[0427]Using routine modifications, the starting materials may be varied
and additional steps employed to produce other compounds provided herein.
Compounds listed in Table I were prepared using such methods. In the
column labeled "IC.sub.50" a * indicates that the IC.sub.50 determined as
described in Example 6 is 1 micromolar or less (i.e., the concentration
of such compounds that is required to provide a 50% decrease in the
fluorescence response of cells exposed to one IC.sub.50 of capsaicin is 1
micromolar or less).
TABLE-US-00002
TABLE 1
Ret. MS
Compound Name IC.sub.50 Time (M + 1)
1 ##STR00105## 2-methyl-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.19 448.15
2 ##STR00106## 2-Methoxymethyl-7-(3- trifluoromethyl-pyridin-2-yl)-
[1,8]naphthyridin-4-yl]-(4- trifluoromethylphenyl)-amine * 1.17 479.16
3 ##STR00107## 2-Methoxymethyl-7-(3- trifluoromethyl-pyridin-2-yl)-
[1,8]naphthyridin-4-yl]-(4-t- butylphenyl)-amine * 1.21 467.2
4 ##STR00108## methyl 2-(methoxymethyl)-4-{[4-
(trifluoromethyl)phenyl]amino}-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridine-3-carboxylate * 1.23 537.23
5 ##STR00109## {4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-yl}methanol * 1.14
465.2
6 ##STR00110## 2-(methoxymethyl)-4-{[4-
(trifluoromethyl)phenyl]amino}-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridine-3-carboxylic acid * 1.21 523.22
7 ##STR00111## 2-(isobutoxymethyl)-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.24 521.25
8 ##STR00112## N-(4-chlorophenyl)-2- (methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.16 445.19
9 ##STR00113## N-(4-fluorophenyl)-2- (methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.14 429.21
10 ##STR00114## N-(4-chloro-3-fluorophenyl)-2- (methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.17 463.19
11 ##STR00115## 4-({2-(methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4- yl}amino)benzonitrile
* 1.1 436.22
12 ##STR00116## 5-{[4- (trifluoromethyl)phenyl]amino}-2-[3-
(trifluoromethyl)pyridin-2- yl]furo[3,4-b]-1,8-naphthyridin- 6(8H)-one *
1.24 491.15
13 ##STR00117## N-[4-(isopropylsulfonyl)phenyl]-2- (methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.11 517.29
14 ##STR00118## 2-(methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.18 480.25
15 ##STR00119## 2-(methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-{4- [(trifluoromethyl)sulfonyl]phenyl}-
1,8-naphthyridin-4-amine * 1.17 543.24
16 ##STR00120## N-(4,4-dimethyl-1,2,3,4- tetrahydroquinolin-7-yl)-2-
(methoxymethyl)-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.18 494.37
17 ##STR00121## 2-(methoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N- (2,4,4-trimethyl-1,2,3,4-
tetrahydroisoquinolin-7-yl)-1,8- naphthyridin-4-amine * 1.06 508.39
18 ##STR00122## 2-isobutoxy-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.26 506.26
19 ##STR00123## N-(4-tert-butylphenyl)-2-isobutoxy-
7-[3-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.28 494.32
20 ##STR00124## 2-chloro-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.34 468.17
21 ##STR00125## 4-[(4-tert-butylphenyl)amino]-7-[3-
(trifluoromethyl)pyridin-2- yl]quinolin-2-ol * 1.29 438.27
22 ##STR00126## N-(4-tert-butylphenyl)-2-chloro-7-
[3-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.36 456.23
23 ##STR00127## N-(4-tert-butylphenyl)-2-morpholin-
4-yl-7-[3-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.24 507.24
24 ##STR00128## 2-{[(2R,6S)-2,6-dimethylmorpholin- 4-yl]methyl}-N-[4-
(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.19 562.23
25 ##STR00129## 2-{[2- (dimethylamino)ethoxy]methyl}-N-
[4-(trifluoromethyl)phenyl]-7-{3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.1 536.22
26 ##STR00130## N-(4-tert-butylphenyl)-2-piperidin-1-
yl-7-[3-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.28 505.25
27 ##STR00131## N~2~butyl-N~4~-(4-tert- butylphenyl)-7-[3-
(trifluoromethyl)pyridin-2- yl]quinoline-2,4-diamine * 1.29 493.28
28 ##STR00132## N-(4-tert-butylphenyl)-2-pyrrolidin-
1-yl-7-[3-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.26 491.25
29 ##STR00133## N~4~-(4-tert-butylphenyl)-N~2~- isopentyl-7-[3-
(trifluoromethyl)pyridin-2- yl]quinoline-2,4-diamine * 1.31 507.29
30 ##STR00134## N-(4-tert-butylphenyl)-2-ethoxy-7-
[3-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.24 466.31
31 ##STR00135## 4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-ol * 1.24 451.22
32 ##STR00136## N-(4-tert-butylphenyl)-2- (isopentyloxy)-7-[3-
(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.3 508.36
33 ##STR00137## N-(4-tert-butylphenyl)-2-propoxy-7-
[3-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.26 480.32
34 ##STR00138## 2-chloro-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.3 469.18
35 ##STR00139## N-[4-(trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 435.35
36 ##STR00140## 2-ethoxy-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.28 479.22
37 ##STR00141## N-(4-tert-butylphenyl)-2-ethoxy-7-
[3-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.26 467.29
38 ##STR00142## 2-ethoxy-N-(4-isopropylphenyl)-7-
[3-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.24 453.27
39 ##STR00143## 2-methyl-7-[3- (trifluoromethyl)pyridin-2-yl]-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.17 450.21
40 ##STR00144## 2-(ethoxymethyl)-N-[4- (trilfuoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.2 493.18
41 ##STR00145## 2-(isopropoxymethyl)-N-[4-
(trifluoromethyl)phenyl]-7-[3- (trilfuoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.22 507.19
42 ##STR00146## 2-[(isopentyloxy)methyl]-N-[4-
(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.26 535.23
43 ##STR00147## 2-(propoxymethyl)-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.22 507.19
44 ##STR00148## 2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.27 522.19
45 ##STR00149## 2-ethoxy-7-[3- (trifluoromethyl)pyridin-2-yl]-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.32 480.15
46 ##STR00150## 2-ethoxy-7-[3- (trifluoromethyl)pyridin-2-yl]-N-{4-
[(trifluoromethyl)sulfonyl]phenyl}- 1,8-naphthyridin-4-amine * 1.31
543.15
47 ##STR00151## N-(4-tert-butylphenyl)-2-methoxy-7-
[3-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.25 453.2
48 ##STR00152## 2-methyl-N-[4- (trifluoromethyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.18 449.16
49 ##STR00153## 2-[(2-methylpyrrolidin-1-yl)methyl]-
N-[4-(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.19 532.26
50 ##STR00154## 2-{[bis(2- methoxyethyl)amino]methyl}-N-[4-
(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.2 580.28
51 ##STR00155## 7-(3-chloropyridin-2-yl)-2- (methoxymethyl)-N-[4-
(trifluoromethyl)phenyl]-1,8- naphthyridin-4-amine * 1.17 445.17
52 ##STR00156## 7-(3-chloropyridin-2-yl)-2- (isobutoxymethyl)-N-[4-
(trifluoromethyl)phenyl]-1,8- naphthyridin-4-amine * 1.25 487.23
53 ##STR00157## 2-(4-{[7-(3-chloropyridin-2-yl)-2-
(methoxymethyl)-1,8-naphthyridin- 4-yl]amino}phenyl)propan-2-ol * 1.13
435.22
54 ##STR00158## N-(4-fluorophenyl)-2- (isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.22 471.25
55 ##STR00159## 2-(azetidin-1-ylmethyl)-N-[4-
(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.18 504.23
56 ##STR00160## 1-[4-({2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-
yl}amino)phenyl]ethanone * 495.27
57 ##STR00161## 2-[4-({2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-
yl}amino)phenyl]propan-2-ol * 1.21 511.3
58 ##STR00162## 2-[(isopropylamino)methyl]-N-[4-
(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.19 506.22
59 ##STR00163## 2-[(isobutylamino)methyl]-N-[4-
(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.19 520.24
60 ##STR00164## 2-{[isobutyl(methyl)amino]methyl}-
N-[4-(trifluoromethyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.21 534.26
61 ##STR00165## N-(5-bromopyridin-2-yl)-2- (isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.27 532.15
62 ##STR00166## 7-(3-fluoropyriidn-2-yl)-2- (methoxymethyl)-N-[4-
(trifluoromethyl)phenyl]-1,8- naphthyridin-4-amine * 1.16 429.16
63 ##STR00167## 1-(4-{[7-(3-chloropyridin-2-yl)-2-
(isobutoxymethyl)-1,8-naphthyridin- 4-yl]amino}phenyl)ethanone * 1.2
461.21
64 ##STR00168## 2-(4-{[7-(3-chloropyridin-2-yl)-2-
(isobutoxymethyl)-1,8-naphthyridin- 4-yl]amino}phenyl)propan-2-ol * 1.21
477.25
65 ##STR00169## 2-(isobutoxymethyl)-N-[4- (methylsulfonyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.15 531.2
66 ##STR00170## 1-{[4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-yl}methoxy)propan-
2-ol * 1.18 523.19
67 ##STR00171## 1-({4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-yl}methoxy)acetone *
1.17 521.17
68 ##STR00172## 4-({2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)-N,N-
dimethylbenzenesulfonamide * 1.19 560.25
69 ##STR00173## N-{[4-({2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-
yl}amino)phenyl]sulfonyl}acetamide 1.16 574.28
70 ##STR00174## N-methyl-N-({4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-
yl}methyl)methanesulfonamide * 1.17 556.22
71 ##STR00175## N-methyl-N-({4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-
yl}methyl)ethanesulfonamide * 1.18 570.24
72 ##STR00176## 2-Iisobutoxymethyl)-N-[4-
(isopropylsulfonyl)phenyl]-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.19 559.29
73 ##STR00177## 2-(isobutoxymethyl)-N-[4- (propylsulfonyl)phenyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.19 559.3
74 ##STR00178## 2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-{4- [(trifluoromethyl)sulfonyl]phenyl}-
1,8-naphthyridin-4-amine * 1.24 585.24
75 ##STR00179## N,2-dimethyl-N-({4-{[4-
(trifluoromethyl)phenyl]amino}-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-2- yl}methyl)propanamide * 1.18 548.19
76 ##STR00180## N-methyl-N-({4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-yl}methyl)glycine *
1.17 495.15
77 ##STR00181## 3-[ethyl({4-{[4- (trifluoromethyl)phenyl]amino]-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-
yl}methyl)amino]propan-1-ol * 1.19 550.05
78 ##STR00182## 3-[isopropyl({4-{[4-
(trifluoromethyl)phenyl]amino}-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-2- yl}methyl)amino]propan-1-ol * 1.19 564.06
79 ##STR00183## 3-[propyl({4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-
yl}methyl)amino]propan-1-ol * 1.21 564.05
80 ##STR00184## N-isobutyl-N-({4-{[4-
(trifluoromethyl)phenyl]amino}-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-2- yl}methyl)methanesulfonamide * 1.22 597.99
81 ##STR00185## N-isobutyl-N-({4-{[4-
(trifluoromethyl)phenyl]amino}-7-[3- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-2-yl}methyl)glycine *
82 ##STR00186## 2-methyl-1-({4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-yl}methoxy)propan-
2-ol * 1.19 537.17
83 ##STR00187## 2-(isobutoxymethyl)-N-(5- methylpyridin-2-yl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.24 468.2
84 ##STR00188## 2-(isobutoxymethyl)-N-pyridin-2-yl-
7-[3-(tirlfuoromethyl)pyridin-2-yl]- 1,8-naphthyridin-4-amine * 1.21
454.19
85 ##STR00189## 2-[6-({2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-2-
yl]propan-2-ol * 1.21 512.23
86 ##STR00190## 2-methyl-3-({4-{[4- (trifluoromethyl)phenyl]amino}-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-2-yl}methoxy)butan-2- ol
* 1.21 551.2
87 ##STR00191## 6-({2-(isobutoxymethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-
yl}amino)nicotinonitrile * 1.22 479.19
88 ##STR00192## (7-[3-(trifluoromethyl)pyridin-2-yl]-
4-{[5-(trifluoromethyl)pyridin-2- yl]amino}-1,8-naphthyridin-2-
yl)methanol * 1.16 466.12
89 ##STR00193## 2-[(dimethylamino)methyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.15 493.17
90 ##STR00194## rel-2-{[(2R,6S)-2,6- dimethylmorpholin-4-yl]methyl}-7-
[3-(trifluoromethyl)pyridin-2-yl]-N-
[5-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.2 563.22
91 ##STR00195## 2-(morpholin-4-ylmethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.17 535.19
92 ##STR00196## 2-(piperidin-1-ylmethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.17 533.21
93 ##STR00197## 2-[(2-methylpyrrolidin-1-yl)methyl]-
7-[3-(trifluoromethyl)pyridin-2-yl]-N-
[5-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.18 533.2
94 ##STR00198## 2-[(diethylamino)methyl]-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.19 521.2
95 ##STR00199## 2-(pyrrolidin-1-ylmethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.19 519.19
96 ##STR00200## 2-methoxy-7-[3- (trifluoromethyl)pyridin-2-yl]-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.31 466.12
97 ##STR00201## 7-[3-(trifluoromethyl)pyridin-2-yl]-4-
{[5-(trifluoromethyl)pyridin-2- yl]amino}-1,8-naphthyridin-2-ol * 1.26
452.08
98 ##STR00202## 2-cyclobutyl-7-[3- (trifluoromethyl)pyridin-2-yl]-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.25 490.14
99 ##STR00203## 2-cyclobutyl-N-(5-methylpyridin-2-
yl)-7-[3-(trifluoromethyl)pyridin-2- yl]-1,8-naphthyridin-4-amine * 1.2
436.18
100 ##STR00204## 6-({2-cyclobutyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-
yl}amino)nicotinonitrile * 1.19 447.16
101 ##STR00205## N-(5-chloropyridin-2-yl)-2- cylcobutyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphtyridin-4-amine * 1.23 456.13
102 ##STR00206## 2-isopropyl-7-[3- (trifluoromethyl)pyridin-2-yl]-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.24 478.15
103 ##STR00207## 2-isopropyl-N-(5-methylpyridin-2-
yl)-7-[3-(trifluoromethyl)pyridin-2- yl]-1,8-naphthyridin-4-amine * 1.19
424.17
104 ##STR00208## 6-({2-isopropyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-
yl}amino)nicotinonitrile * 1.17 435.16
105 ##STR00209## N-(5-chloropyriidn-2-yl)-2- isopropyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.22 444.12
106 ##STR00210## 7-[3-(trifluoromethyl)pyridin-2-yl]-N-
[5-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.16 436.12
107 ##STR00211## 2-methoxy-7-[3- (trifluoromethyl)pyridin-2-yl]-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,5- naphthyriidn-4-amine 1.2 466.16
108 ##STR00212## 7-[3-(trifluoromethyl)pyridin-2-yl]-N-
[5-(trifluoromethyl)pyridin-2-yl]-1,5- naphthyridin-4-amine * 1.29 436.14
109 ##STR00213## 7-[3-(trifluoromethyl)pyridin-2-yl]-N-
[5-(trifluoromethyl)pyridin-2- yl]quinolin-4-amine * 1.19 435.15
110 ##STR00214## 2-ethyl-7-[3-(trifluoromethyl)pyridin-
2-yl]-N-[5-(trifluoromethyl)pyridin-2- yl]-1,8-naphthyridin-4-amine * 1.2
464.16
111 ##STR00215## 1-[6-({2-ethyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]ethanone * 1.16 438.19
112 ##STR00216## 2-[6-({2-ethyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]propan-2-ol * 1.16 454.25
113 ##STR00217## 3-[3-(trifluoromethyl)pyridin-2-yl]-N-
[5-(trifluoromethyl)pyridin-2- yl]pyrido[2,3-b]pyrazin-8-amine * 1.23
437.12
114 ##STR00218## 2-propyl-7-[3- (trifluoromethyl)pyridin-2-yl]-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.25 478.16
115 ##STR00219## 1-[6-({2-propyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]ethanone * 1.19 452.19
116 ##STR00220## 1-[6-({2-isopropyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]ethanone * 1.18 452.2
117 ##STR00221## 2-[6-({2-propyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]propan-2-ol * 1.19 468.24
118 ##STR00222## 2-[6-({2-isopropyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]propan-2-ol * 1.18 468.22
119 ##STR00223## 2-(1-methoxyethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.23 494.17
120 ##STR00224## 1-[6-({2-(1-methoxyethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]ethanone * 1.17 468.2
121 ##STR00225## 2-[6-({2-(1-methoxyethyl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-yl}amino)pyridin-3-
yl]propan-2-ol * 1.15 484.24
122 ##STR00226## N-(5-chloropyridin-2-yl)-2-propyl-7-
[3-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine * 1.24 444.13
123 ##STR00227## N-[5-(methylsulfonyl)pyridin-2-yl]-2-
propyl-7-[3-(trifluoromethyl)pyridin- 2-yl]-1,8-naphthyridin-4-amine *
1.16 488.15
124 ##STR00228## 2-(1-methylpiperidin-3-yl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 1.2 533.19
125 ##STR00229## 7-[3-(trifluoromethyl)pyridin-2-yl]-4-
{[5-(trifluoromethyl)pyridin-2- yl]amino}-1,8-naphthyridine-2-
carbonitrile * 1.31 461.11
126 ##STR00230## 7-[3-(trifluoromethyl)pyridin-2-yl]-4-
{[5-(trifluoromethyl)pyridin-2- yl]amino}-1,8-naphthyridine-2-
carboxamide *
127 ##STR00231## 7-[3-(trifluoromethyl)pyridin-2-yl]-4-
{[5-(trifluoromethyl)pyridin-2- yl]amino}-1,8-naphthyridine-2- carboxylic
acid
128 ##STR00232## N-(5-ethylpyridin-2-yl)-2-propyl-7-
[3-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine *
129 ##STR00233## 2-morpholin-4-yl-7-[3-
(trifluoromethyl)pyridin-2-yl]-N-[5- (trifluoromethyl)pyridin-2-yl]-1,8-
naphthyridin-4-amine * 521.1
130 ##STR00234## N~2~-isobutyl-7-[3-
(trifluoromethyl)pyridin-2-yl]-N~4~-
[5-(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridine-2,4-diamine * 507.1
131 ##STR00235## N-[5-(trifluoromethyl)pyrazin-2-yl]-
7-[3-(trifluoromethyl)pyridin-2-yl]- 1,8-naphthyridin-4-amine * 437.04
132 ##STR00236## 7-[3-(trifluoromethyl)pyridin-2-yl]-N-
[5-(trifluoromethyl)pyrimidin-2-yl]- 1,8-naphthyridin-4-amine * 437.04
133 ##STR00237## 1-(7-[3-(trifluoromethyl)pyridin-2-
yl]-4-{[5-(trifluoromethyl)pyridin-2- yl]amino}-1,8-naphthyridin-2-
yl)ethanone *
134 ##STR00238## N-[6-(trifluoromethyl)pyridazin-3-
yl]-7-[3-(trifluoromethyl)pyridin-2- yl]-1,8-naphthyridin-4-amine
135 ##STR00239## 7-(3-methylpyridin-2-yl)-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine *
136 ##STR00240## 7-(3-chloropyridin-2-yl)-N-[5-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine *
137 ##STR00241## 7-(3-methylpyridin-2-yl)-N-[5-
(trifluoromethyl)pyrimidin-2-yl]-1,8- naphthyridin-4-amine *
138 ##STR00242## 7-(3-chloropyridin-2-yl)-N-[5-
(trifluoromethyl)pyrazin-2-yl]-1,8- naphthyridin-4-amine *
139 ##STR00243## N-(5-chloropyridin-2-yl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine *
140 ##STR00244## N-(5-methylpyridin-2-yl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine *
141 ##STR00245## 1-[6-({7-[3-(trifluoromethyl)pyridin-
2-yl]-1,8-naphthyridin-4- yl]amino)pyridin-3-yl]ethanone *
142 ##STR00246## 7-[3-(trifluoromethyl)pyridin-2-yl]-N-
[6-(trifluoromethyl)pyridin-3-yl]-1,8- naphthyridin-4-amine *
143 ##STR00247## N-(5-ethylpyridin-2-yl)-7-[3-
(trifluoromethyl)pyridin-2-yl]-1,8- naphthyridin-4-amine *
144 ##STR00248## 7-(3-methylpyridin-2-yl)-N-[5-
(trifluoromethyl)pyrazin-2-yl]-1,8- naphthyridin-4-amine *
145 ##STR00249## 7-(3-chloropyridin-2-yl)-N-[5-
(trifluoromethyl)pyrimidin-2-yl]-1,8- naphthyridin-4-amine *
Example 4
VR1-Transfected Cells and Membrane Preparations
[0428]This Example illustrates the preparation of VR1-transfected cells
and membrane preparations for use in binding assays (Example 5) and
functional assays (Example 6).
[0429]A cDNA encoding full length human capsaicin receptor (SEQ ID NO:1, 2
or 3 of U.S. Pat. No. 6,482,611) was subcloned in the plasmid pBK-CMV
(Stratagene, La Jolla, Calif.) for recombinant expression in mammalian
cells.
[0430]Human embryonic kidney (HEK293) cells were transfected with the
pBK-CMV expression construct encoding the full length human capsaicin
receptor using standard methods. The transfected cells were selected for
two weeks in media containing G418 (400 .mu.g/ml) to obtain a pool of
stably transfected cells. Independent clones were isolated from this pool
by limiting dilution to obtain clonal stable cell lines for use in
subsequent experiments.
[0431]For radioligand binding experiments, cells were seeded in T175 cell
culture flasks in media without antibiotics and grown to approximately
90% confluency. The flasks were then washed with PBS and harvested in PBS
containing 5 mM EDTA. The cells were pelleted by gentle centrifugation
and stored at -80.degree. C. until assayed.
[0432]Previously frozen cells were disrupted with the aid of a tissue
homogenizer in ice-cold HEPES homogenization buffer (5 mM KCl 5, 5.8 mM
NaCl, 0.75 mM CaCl.sub.2, 2 mM MgCl.sub.2, 320 mM sucrose, and 10 mM
HEPES pH 7.4). Tissue homogenates were first centrifuged for 10 minutes
at 1000.times.g (4.degree. C.) to remove the nuclear fraction and debris,
and then the supernatant from the first centrifugation is further
centrifuged for 30 minutes at 35,000.times.g (4.degree. C.) to obtain a
partially purified membrane fraction. Membranes were resuspended in the
HEPES homogenization buffer prior to the assay. An aliquot of this
membrane homogenate is used to determine protein concentration via the
Bradford method (BIO-RAD Protein Assay Kit, #500-0001, BIO-RAD, Hercules,
Calif.).
Example 5
Capsaicin Receptor Binding Assay
[0433]This Example illustrates a representative assay of capsaicin
receptor binding that may be used to determine the binding affinity of
compounds for the capsaicin (VR1) receptor.
[0434]Binding studies with [.sup.3H] Resiniferatoxin (RTX) are carried out
essentially as described by Szallasi and Blumberg (1992) J. Pharmacol.
Exp. Ter. 262:883-888. In this protocol, non-specific RTX binding is
reduced by adding bovine alpha.sub.1 acid glycoprotein (100 g per tube)
after the binding reaction has been terminated.
[0435][.sup.3H] RTX (37 Ci/mmol) is synthesized by and obtained from the
Chemical Synthesis and Analysis Laboratory, National Cancer
Institute-Frederick Cancer Research and Development Center, Frederick,
Md. [.sup.3H] RTX may also be obtained from commercial vendors (e.g.,
Amersham Pharmacia Biotech, Inc.; Piscataway, N.J.).
[0436]The membrane homogenate of Example 4 is centrifuged as before and
resuspended to a protein concentration of 333 .mu.g/ml in homogenization
buffer. Binding assay mixtures are set up on ice and contain [.sup.3H]RTX
(specific activity 2200 mCi/ml), 2 .mu.l non-radioactive test compound,
0.25 mg/ml bovine serum albumin (Cohn fraction V), and
5.times.10.sup.4-1.times.10.sup.5 VR1-transfected cells. The final volume
is adjusted to 500 .mu.l (for competition binding assays) or 1,000 .mu.l
(for saturation binding assays) with the ice-cold HEPES homogenization
buffer solution (pH 7.4) described above. Non-specific binding is defined
as that occurring in the presence of 1 .mu.M non-radioactive RTX (Alexis
Corp.; San Diego, Calif.). For saturation binding, [.sup.3H]RTX is added
in the concentration range of 7-1,000 pM, using 1 to 2 dilutions.
Typically 11 concentration points are collected per saturation binding
curve.
[0437]Competition binding assays are performed in the presence of 60 pM
[.sup.3H]RTX and various concentrations of test compound. The binding
reactions are initiated by transferring the assay mixtures into a
37.degree. C. water bath and are terminated following a 60 minute
incubation period by cooling the tubes on ice. Membrane-bound RTX is
separated from free, as well as any alpha.sub.1-acid glycoprotein-bound
RTX, by filtration onto WALLAC glass fiber filters (PERKIN-ELMER,
Gaithersburg, Md.) which were pre-soaked with 1.0% PEI
(polyethyleneimine) for 2 hours prior to use. Filters are allowed to dry
overnight then counted in a WALLAC 1205 BETA PLATE counter after addition
of WALLAC BETA SCINT scintillation fluid.
[0438]Equilibrium binding parameters are determined by fitting the
allosteric Hill equation to the measured values with the aid of the
computer program FIT P (Biosoft, Ferguson, Mo.) as described by Szallasi,
et al. (1993) J. Pharmacol. Exp. Ther. 266:678-683. Compounds provided
herein generally exhibit K.sub.i values for capsaicin receptor of less
than 1 .mu.M, 100 nM, 50 nM, 25 nM, 10 nM, or 1 nM in this assay.
Example 6
Calcium Mobilization Assay
[0439]This Example illustrates a representative calcium mobilization assay
for use in monitoring the response of cells expressing capsaicin receptor
to capsaicin and other vanilloid ligands of the capsaicin receptor, as
well as for evaluating test compounds for agonist and antagonist
activity.
[0440]Cells transfected with expression plasmids (as described in Example
4) and thereby expressing human capsaicin receptor are seeded and grown
to 70-90% confluency in FALCON black-walled, clear-bottomed 96-well
plates (#3904, BECTON-DICKINSON, Franklin Lakes, N.J.). The culture
medium is emptied from the 96 well plates and FLUO-3 AM calcium sensitive
dye (Molecular Probes, Eugene, Oreg.) is added to each well (dye
solution: 1 mg FLUO-3 AM, 440 .mu.L DMSO and 440 .mu.l 20% pluronic acid
in DMSO, diluted 1:250 in Krebs-Ringer HEPES (KRH) buffer (25 mM HEPES, 5
mM KCl, 0.96 mM NaH.sub.2PO.sub.4, 1 mM MgSO.sub.4, 2 mM CaCl.sub.2, 5 mM
glucose, 1 mM probenecid, pH 7.4), 501 diluted solution per well). Plates
are covered with aluminum foil and incubated at 37.degree. C. for 1-2
hours in an environment containing 5% CO.sub.2. After the incubation, the
dye is emptied from the plates, and the cells are washed once with KRH
buffer, and resuspended in KRH buffer.
[0441]Agonist (e.g., olvanil, capsaicin, or RTX)-induced calcium
mobilization is monitored using either FLUOROSKAN ASCENT (Labsystems,
Franklin, Mass.) or FLIPR (fluorometric imaging plate reader system,
Molecular Devices, Sunnyvale, Calif.) instruments. Varying concentrations
of the antagonists ruthenium red or capsazepine (RBI; Natick, Mass.) are
added to cells concurrently with agonist (e.g., 25-50 nM capsaicin). For
agonist-induced calcium responses, data obtained between 30 and 60
seconds after agonist application are used to generate the IC.sub.50
values. KALEIDAGRAPH software (Synergy Software, Reading, Pa.) is used to
fit the data to the equation:
y=a*(1/(1+(b/x).sup.c))
to determine the IC.sub.50 for the response. In this equation, y is the
maximum fluorescence signal, x is the concentration of the agonist or
antagonist, a is the E.sub.max, b corresponds to the IC.sub.50 value and
c is the Hill coefficient.
[0442]To measure the ability of a test compound to antagonize (inhibit)
the response of cells expressing capsaicin receptors to capsaicin or
other vanilloid agonist, the IC.sub.50 of capsaicin is first determined.
An additional 20 .mu.l of KRH buffer and 1 .mu.l DMSO is added to each
well of cells, prepared as described above. 100 .mu.l capsaicin in KRH
buffer is automatically transferred by the FLIPR instrument to each well.
An 8-point concentration response curve, with final capsaicin
concentrations of 1 nM to 3 .mu.M, is used to determine capsaicin
IC.sub.50.
[0443]Test compounds are dissolved in DMSO, diluted in 20 .mu.l KRH buffer
so that the final concentration of test compounds in the assay well is
between 1 .mu.M and 5 .mu.M, and added to cells prepared as described
above. The 96 well plates containing prepared cells and test compounds
are incubated in the dark, at room temperature for 0.5 to 6 hours. It is
important that the incubation not continue beyond 6 hours. Just prior to
determining the fluorescence response, 100 .mu.l capsaicin in KRH buffer
at twice the IC.sub.50 concentration determined from the concentration
response curve is automatically added by the FLIPR instrument to each
well of the 96 well plate for a final sample volume of 200 .mu.l and a
final capsaicin concentration equal to the IC.sub.50. The final
concentration of test compounds in the assay wells is between 1 .mu.M and
5 .mu.M. Typically cells exposed to one IC.sub.50 of capsaicin exhibit a
fluorescence response of about 10,000 Relative Fluorescence Units.
Antagonists of the capsaicin receptor decrease this response by at least
about 20%, preferably by at least about 50%, and most preferably by at
least 80% as compared to matched control. The concentration of antagonist
required to provide a 50% decrease is the IC.sub.50 for the antagonist,
and is preferably below 1 micromolar, 100 nanomolar, 10 nanomolar or 1
nanomolar.
[0444]The ability of a compound to act as an agonist of the capsaicin
receptor is determined by measuring the fluorescence response of cells
expressing capsaicin receptors, using the methods described above, in the
absence of capsaicin, RTX, or other capsaicin receptor agonists.
Compounds that cause cells to exhibit fluorescence above background are
capsaicin receptor agonists. Certain preferred compounds of the present
invention are antagonists that are essentially free of agonist activity
as demonstrated by the absence of detectable agonist activity in such an
assay at compound concentrations below 4 nM, more preferably at
concentrations below 10 .mu.M and most preferably at concentrations less
than or equal to 100 .mu.M.
Example 7
Microsomal In Vitro Half-Life
[0445]This Example illustrates the evaluation of compound half-life values
(t.sub.1/2 values) using a representative liver microsomal half-life
assay.
[0446]Pooled human liver microsomes are obtained from XenoTech LLC, 3800
Cambridge St., Kansas City, Kans. 66103 (catalog #H0610). Such liver
microsomes may also be obtained from In Vitro Technologies (Baltimore,
Md.) or Tissue Transformation Technologies (Edison, N.J.). Six test
reactions are prepared, each containing 25 .mu.L microsomes, 5 .mu.L of a
100 .mu.M solution of test compound, and 399 .mu.L 0.1 M phosphate buffer
(19 mL 0.1 M NaH.sub.2PO.sub.4, 81 mL 0.1 M Na.sub.2HPO.sub.4, adjusted
to pH 7.4 with H.sub.3PO.sub.4). A seventh reaction is prepared as a
positive control containing 25 .mu.L microsomes, 399 .mu.L 0.1 M
phosphate buffer, and 5 .mu.L of a 100 .mu.M solution of a compound with
known metabolic properties (e.g., DIAZEPAM or CLOZAPINE). Reactions are
preincubated at 39.degree. C. for 10 minutes.
[0447]CoFactor Mixture is prepared by diluting 16.2 mg NADP and 45.4 mg
Glucose-6-phosphate in 4 mL 100 mM MgCl.sub.2. Glucose-6-phosphate
dehydrogenase solution is prepared by diluting 214.3 .mu.L
glucose-6-phosphate dehydrogenase suspension (Boehringer-Manheim catalog
no. 0737224, distributed by Roche Molecular Biochemicals, Indianapolis,
Ind.) into 1285.7 .mu.L distilled water. 71 .mu.L Starting Reaction
Mixture (3 mL CoFactor Mixture; 1.2 mL Glucose-6-phosphate dehydrogenase
solution) is added to 5 of the 6 test reactions and to the positive
control. 71 .mu.L 100 mM MgCl.sub.2 is added to the sixth test reaction,
which is used as a negative control. At each time point (0, 1, 3, 5, and
10 minutes), 75 .mu.L of each reaction mix is pipetted into a well of a
96-well deep-well plate containing 75 .mu.L ice-cold acetonitrile.
Samples are vortexed and centrifuged 10 minutes at 3500 rpm (Sorval T
6000D centrifuge, H1000B rotor). 75 .mu.L of supernatant from each
reaction is transferred to a well of a 96-well plate containing 150 .mu.L
of a 0.5 .mu.M solution of a compound with a known LCMS profile (internal
standard) per well. LCMS analysis of each sample is carried out and the
amount of unmetabolized test compound is measured as AUC, compound
concentration vs. time is plotted, and the t.sub.1/2 value of the test
compound is extrapolated.
[0448]Preferred compounds of the present invention exhibit in vitro
t.sub.1/2 values of greater than 10 minutes and less than 4 hours,
preferably between 30 minutes and 1 hour, in human liver microsomes.
Example 8
MDCK Toxicity Assay
[0449]This Example illustrates the evaluation of compound toxicity using a
Madin Darby canine kidney (MDCK) cell cytotoxicity assay.
[0450]1 .mu.L of test compound is added to each well of a clear bottom
96-well plate (PACKARD, Meriden, Conn.) to give final concentration of
compound in the assay of 10 micromolar, 100 micromolar or 200 micromolar.
Solvent without test compound is added to control wells.
[0451]MDCK cells, ATCC no. CCL-34 (American Type Culture Collection,
Manassas, Va.), are maintained in sterile conditions following the
instructions in the ATCC production information sheet. Confluent MDCK
cells are trypsinized, harvested, and diluted to a concentration of
0.1.times.10.sup.6 cells/ml with warm (37.degree. C.) medium (VITACELL
Minimum Essential Medium Eagle, ATCC catalog #30-2003). 100 .mu.L of
diluted cells is added to each well, except for five standard curve
control wells that contain 100 .mu.L of warm medium without cells. The
plate is then incubated at 37.degree. C. under 95% O.sub.2, 5% CO.sub.2
for 2 hours with constant shaking. After incubation, 50 .mu.L of
mammalian cell lysis solution is added per well, the wells are covered
with PACKARD TOPSEAL stickers, and plates are shaken at approximately 700
rpm on a suitable shaker for 2 minutes.
[0452]Compounds causing toxicity will decrease ATP production, relative to
untreated cells. The PACKARD, (Meriden, Conn.) ATP-LITE-M Luminescent ATP
detection kit, product no. 6016941, is generally used according to the
manufacturer's instructions to measure ATP production in treated and
untreated MDCK cells. PACKARD ATP LITE-M reagents are allowed to
equilibrate to room temperature. Once equilibrated, the lyophilized
substrate solution is reconstituted in 5.5 mls of substrate buffer
solution (from kit). Lyophilized ATP standard solution is reconstituted
in deionized water to give a 10 mM stock. For the five control wells, 10
.mu.L of serially diluted PACKARD standard is added to each of the
standard curve control wells to yield a final concentration in each
subsequent well of 200 nM, 100 nM, 50 nM, 25 nM and 12.5 nM. PACKARD
substrate solution (50 .mu.L) is added to all wells, which are then
covered, and the plates are shaken at approximately 700 rpm on a suitable
shaker for 2 minutes. A white PACKARD sticker is attached to the bottom
of each plate and samples are dark adapted by wrapping plates in foil and
placing in the dark for 10 minutes. Luminescence is then measured at
22.degree. C. using a luminescence counter (e.g., PACKARD TOPCOUNT
Microplate Scintillation and Luminescence Counter or TECAN SPECTRAFLUOR
PLUS), and ATP levels calculated from the standard curve. ATP levels in
cells treated with test compound(s) are compared to the levels determined
for untreated cells. Cells treated with 10 .mu.M of a preferred test
compound exhibit ATP levels that are at least 80%, preferably at least
90%, of the untreated cells. When a 100 .mu.M concentration of the test
compound is used, cells treated with preferred test compounds exhibit ATP
levels that are at least 50%, preferably at least 80%, of the ATP levels
detected in untreated cells.
Example 9
Dorsal Root Ganglion Cell Assay
[0453]This Example illustrates a representative dorsal root ganglian cell
assay for evaluating VR1 antagonist activity of a compound.
[0454]DRG are dissected from neonatal rats, dissociated and cultured using
standard methods (Aguayo and White (1992) Brain Research 570:61-67).
After 48 hour incubation, cells are washed once and incubated for 30-60
minutes with the calcium sensitive dye Fluo 4 AM (2.5-10 ug/ml; TefLabs,
Austin, Tex.). Cells are then washed once, and various concentrations of
compound is added to the cells. Addition of capsaicin to the cells
results in a VR1-dependent increase in intracellular calcium levels which
is monitored by a change in Fluo-4 fluorescence with a fluorometer. Data
are collected for 60-180 seconds to determine the maximum fluorescent
signal. Fluorescent signal is then plotted as a function of compound
concentration to identify the concentration required to achieve a 50%
inhibition of the capsaicin-activated response, or IC.sub.50. Antagonists
of the capsaicin receptor preferably have an IC.sub.50 below 1
micromolar, 100 nanomolar, 10 nanomolar or 1 nanomolar.
Example 10
Animal Models for Determining Pain Relief
[0455]This Example illustrates representative methods for assessing the
degree of pain relief provided by a compound.
A. Pain Relief Testing
[0456]The following methods may be used to assess pain relief.
Mechanical Allodynia
[0457]Mechanical allodynia (an abnormal response to an innocuous stimulus)
is assessed essentially as described by Chaplan et al. (1994) J.
Neurosci. Methods 53:55-63 and Tal and Eliav (1998) Pain 64(3):511-518. A
series of von Frey filaments of varying rigidity (typically 8-14
filaments in a series) are applied to the plantar surface of the hind paw
with just enough force to bend the filament. The filaments are held in
this position for no more than three seconds or until a positive
allodynic response is displayed by the rat. A positive allodynic response
consists of lifting the affected paw followed immediately by licking or
shaking of the paw. The order and frequency with which the individual
filaments are applied are determined by using Dixon up-down method.
Testing is initiated with the middle hair of the series with subsequent
filaments being applied in consecutive fashion, ascending or descending,
depending on whether a negative or positive response, respectively, is
obtained with the initial filament.
[0458]Compounds are effective in reversing or preventing mechanical
allodynia-like symptoms if rats treated with such compounds require
stimulation with a Von Frey filament of higher rigidity strength to
provoke a positive allodynic response as compared to control untreated or
vehicle treated rats. Alternatively, or in addition, testing of an animal
in chronic pain may be done before and after compound administration. In
such an assay, an effective compound results in an increase in the
rigidity of the filament needed to induce a response after treatment, as
compared to the filament that induces a response before treatment or in
an animal that is also in chronic pain but is left untreated or is
treated with vehicle. Test compounds are administered before or after
onset of pain. When a test compound is administered after pain onset,
testing is performed 10 minutes to three hours after administration.
Mechanical Hyperalgesia
[0459]Mechanical hyperalgesia (an exaggerated response to painful
stimulus) is tested essentially as described by Koch et al. (1996)
Analgesia 2(3):157-164. Rats are placed in individual compartments of a
cage with a warmed, perforated metal floor. Hind paw withdrawal duration
(i.e., the amount of time for which the animal holds its paw up before
placing it back on the floor) is measured after a mild pinprick to the
plantar surface of either hind paw.
[0460]Compounds produce a reduction in mechanical hyperalgesia if there is
a statistically significant decrease in the duration of hindpaw
withdrawal. Test compound may be administered before or after onset of
pain. For compounds administered after pain onset, testing is performed
10 minutes to three hours after administration.
Thermal Hyperalgesia
[0461]Thermal hyperalgesia (an exaggerated response to noxious thermal
stimulus) is measured essentially as described by Hargreaves et al.
(1988) Pain. 32(1):77-88. Briefly, a constant radiant heat source is
applied the animals' plantar surface of either hind paw. The time to
withdrawal (i.e., the amount of time that heat is applied before the
animal moves its paw), otherwise described as thermal threshold or
latency, determines the animal's hind paw sensitivity to heat.
[0462]Compounds produce a reduction in thermal hyperalgesia if there is a
statistically significant increase in the time to hindpaw withdrawal
(i.e., the thermal threshold to response or latency is increased). Test
compound may be administered before or after onset of pain. For compounds
administered after pain onset, testing is performed 10 minutes to three
hours after administration.
B. Pain Models
[0463]Pain may be induced using any of the following methods, to allow
testing of analgesic efficacy of a compound. In general, compounds
provided herein result in a statistically significant reduction in pain
as determined by at least one of the previously described testing
methods, using male SD rats and at least one of the following models.
Acute Inflammatory Pain Model
[0464]Acute inflammatory pain is induced using the carrageenan model
essentially as described by Field et al. (1997) Br. J. Pharmacol.
121(8):1513-1522. 100-200 .mu.l of 1-2% carrageenan solution is injected
into the rats' hind paw. Three to four hours following injection, the
animals' sensitivity to thermal and mechanical stimuli is tested using
the methods described above. A test compound (0.01 to 50 mg/kg) is
administered to the animal, prior to testing, or prior to injection of
carrageenan. The compound can be administered orally or through any
parenteral route, or topically on the paw. Compounds that relieve pain in
this model result in a statistically significant reduction in mechanical
allodynia and/or thermal hyperalgesia.
Chronic Inflammatory Pain Model
[0465]Chronic inflammatory pain is induced using one of the following
protocols: [0466]1. Essentially as described by Bertorelli et al.
(1999) Br. J. Pharmacol. 128(6):1252-1258, and Stein et al. (1998)
Pharmacol. Biochem. Behav. 31(2):455-51, 200 .mu.L Complete Freund's
Adjuvant (0.1 mg heat killed and dried M. Tuberculosis) is injected to
the rats' hind paw: 100 .mu.L into the dorsal surface and 100 .mu.L into
the plantar surface. [0467]2. Essentially as described by Abbadie et al.
(1994) J. Neurosci. 14(10):5865-5871 rats are injected with 150 .mu.L of
CFA (1.5 mg) in the tibio-tarsal joint.
[0468]Prior to injection with CFA in either protocol, an individual
baseline sensitivity to mechanical and thermal stimulation of the
animals' hind paws is obtained for each experimental animal.
[0469]Following injection of CFA, rats are tested for thermal
hyperalgesia, mechanical allodynia and mechanical hyperalgesia as
described above. To verify the development of symptoms, rats are tested
on days 5,6, and 7 following CFA injection. On day 7, animals are treated
with a test compound, morphine or vehicle. An oral dose of morphine of
1-5 mg/kg is suitable as positive control. Typically, a dose of 0.01-50
mg/kg of test compound is used. Compounds can be administered as a single
bolus prior to testing or once or twice or three times daily, for several
days prior to testing. Drugs are administered orally or through any
parenteral route, or applied topically to the animal.
[0470]Results are expressed as Percent Maximum Potential Efficacy (MPE).
0% MPE is defined as analgesic effect of vehicle, 100% MPE is defined as
an animal's return to pre-CFA baseline sensitivity. Compounds that
relieve pain in this model result in a MPE of at least 30%.
Chronic Neuropathic Pain Model
[0471]Chronic neuropathic pain is induced using the chronic constriction
injury (CCI) to the rat's sciatic nerve essentially as described by
Bennett and Xie (1988) Pain 33:87-107. Rats are anesthetized (e.g. with
an intraperitoneal dose of 50-65 mg/kg pentobarbital with additional
doses administered as needed). The lateral aspect of each hind limb is
shaved and disinfected. Using aseptic technique, an incision is made on
the lateral aspect of the hind limb at the mid thigh level. The biceps
femoris is bluntly dissected and the sciatic nerve is exposed. On one
hind limb of each animal, four loosely tied ligatures are made around the
sciatic nerve approximately 1-2 mm apart. On the other side the sciatic
nerve is not ligated and is not manipulated. The muscle is closed with
continuous pattern and the skin is closed with wound clips or sutures.
Rats are assessed for mechanical allodynia, mechanical hyperalgesia and
thermal hyperalgesia as described above.
[0472]Compounds that relieve pain in this model result in a statistically
significant reduction in mechanical allodynia, mechanical hyperalgesia
and/or thermal hyperalgesia when administered (0.01-50 mg/kg, orally,
parenterally or topically) immediately prior to testing as a single
bolus, or for several days: once or twice or three times daily prior to
testing.
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