Synthesis of Optically Active 2-(N-Benzyl-N-methylamino)ethyl Methyl 2, 6-Dimethyl-4-(m-nitrophenyl)-1, 4-dihydropyridine-3, 5-dicarboxylate (Nicardipine)

Abstract

(+)- and (-)-2-(N-benzyl-N-methylamino)ethyl methyl 2, 6-dimethyl-4-(m-nitrophenyl)-1, 4-dihydropyridine-3, 5-dicarboxylate (6) (nicardipine) were synthesized from (-)- and (+)- 1-ethoxymethyl-5-methoxycarbonyl-2, 6-dimethyl-4-(m-nitrophenyl)-1, 4-dihydropyridine-3-carboxylic acid (3), respectively. Resolution of 3 was carried out using cinchonidine and cinchonine as resolving agents. The vertebral vasodilating activity of (+)-YC-93 (the hydrochloride of (+)-(6)) was about 3 times that of (-)-YC-93.