Synthesis of some C-3,4,5-substituted 2,6-dimethyl-1,4-dihydropyridines (4-DHPs)

Abstract

A series of C-3,4,5-substituted 2,6-dimethyl-1,4-dihydropyridines ( 1,4-DHPs) with pharmacological properties were prepared by a variation from the classical Hantzsch synthesis. The procedure involves treatment of the respective aldehyde with either ethyl-3-aminocrotonate or 3-aminocrotonitrile in anhydrous acetic acid at temperatures not exceeding 60 degrees C, thus minimizing by-product formation. The structures of title compounds were elucidated by H-1 NMR, C-13 NMR, FTIR, and elemental analysis.