An intermediate compound is disclosed that is useful in the preparation of a lipid-peroxidation inhibiting substance and that is selected from the group consisting of: 2,4-bis[1-adamantylamino]-6-(1-piperazinyl)pyrimidine; and 4,6-bis(1-adamantylamino)-2-(1-piperazinyl)pyrimidine; or a pharmaceutically acceptable acid addition salt thereof.