2-Butyl-5-chloro-1H-imidazole-4-carboxaldehyde may be used in the preparation of the following symmetrical esters of dialkyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate; · dimethyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · diethyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · diisopropyl 4-(2-butyl-5-chloro-1Himidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · diisobutyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · di-tert-butyl 4-(2-butyl-5-chloro-1Himidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · bis(2-methoxyethyl) 4-(2-butyl-5-chloro-1Himidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate 2-Butyl-5-chloro-1H-imidazole-4-carboxaldehyde may be used in the preparation of the following symmetrical esters of dialkyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate; · dimethyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · diethyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · diisopropyl 4-(2-butyl-5-chloro-1Himidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · diisobutyl 4-(2-butyl-5-chloro-1H-imidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · di-tert-butyl 4-(2-butyl-5-chloro-1Himidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate · bis(2-methoxyethyl) 4-(2-butyl-5-chloro-1Himidazol-4-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate