Synthesis of 1,4-dihydropyridine derivatives with vasodilating activities (I)

□Asymmetric 2,6-dimethyl-4-aryl-1,4-dihydropyridine-3,5-dicarboxylate with [N-(3,4-methylenedioxybenzyl)-N-methyl] aminoethyl group as the ester moiety and related 1,4-dihydropyridine derivatives were prepared and tested for the effects on vascular smooth muscles. 2,6-dimethyl-4-(3′-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-[N-(3′, 4′-methylenedioxybenzyl)-N-methyl] aminoethyl ester 5-methyl ester (11) and 2,6-dimethyl-4-(3′-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-[N-2′,3′-methylenedioxybenzyl)-N-methyl] aminoethyl ester 5-ethyl ester (15) showed potent vasodilating activities. IC₅₀ (10⁻⁸ M) was 2.6 and 2.7 for11 and15, compared with 3.5 for nicardipine.