1,4-디하이드로피리딘 산류의 합성

Synthesis of 1,4-Dihydropyridine Carboxylic Acids

2,6-Dimethyl-4-(3''-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-methyl 5-(2''-phenylsulfinyl) ethyl ester (10) or 2,6-Dimethyl-4-(2''or 3''-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-alkyl 5-(2-methylsulfonyl) ethyl ester (14a, b, c) were hydrolyzed by treatment with NaOH in aqueous EtOH solution to give 2,6-Dimethyl-4-(3''-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monomethyl ester (4b), 2,6-Dimethyl-4-(2''-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monomethyl ester (4c) and 2,6-Dimethyl-4-(2'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monoisopropyl ester (4d) in 80-90% yield. By the same procedure, 2,6-Dimethyl-4-(3''-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3,5-bis(2''-methylsulfonyl) ethyl ester (15) gave 2,6-Dimethyl-4-(3''-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid (4e) in 96% yield.