Process for the preparation of derivatives of 1,4-dihydropyridine-3-carboxylic acid, derivatives of 1,4-dihydropyridine-3-carboxylic acid and the use of these derivatives for the preparation of 1,4-dihydropyridine-3,5-dicarboxylates

摘要

1,4-Dihydro-3-carboxylic acid derivatives of the formula IMAGE wherein R represents optionally substituted aryl or heterocyclic radicals, R¹ and R² which are the same or different, represent hydrogen, an alkyl, aryl or an aralkyl radical and X stands for a carboxy group, a substituted carbonyl group or for substituted thio, sulfinyl and sulfonyl groups, are by alkaline hydrolysis of alkyl esters of 1,4-dihydropyridine-3-carboxylic acid, which have an electron-withdrawing group in the alkyl part, such as the cyano group. They have a circulatory effect. Some of the compounds of the above formula are new, e.g. those in which R represents a 2-nitrophenyl, 3-nitrophenyl, 2-chlorophenyl, 2-trifluorophenly or a 2-methylmercaptopyridyl radical, R¹ and R² represent methyl and, X represents a carboxy or an alkoxycarbonyl group, in which the alkyl radical contains up to 6 carbon atoms and is optionally interrupted by an oxygen atom in the chain or is substituted by 1 to 2 trifluoromethyl groups or by the radical -N (methyl, benzyl).