4-{3-(Dimethylamino)-1-[2-(dimethylamino)vinyl]prop-2-enylidene}-2-phenyl-1,3-oxazol-5(4H)-one and 5-{3-(dimethylamino)-1-[2-(dimethylamino)vinyl]prop-2-enylidene}-3-methyl-2-thioxo-1,3-thiazolidin-4-one in the synthesis of 1,4-dihydropyridine deriva

摘要

4-{3-(Dimethylamino)-1-[2-(dimethylamino)vinyl]prop-2-enylidene}-2-phenyl-1,3-oxazol-5(4H)-one (3) and 5-{3-(dimethylamino)-1-[2-(dimethylamino)vinyl]prop-2-enylidene}-3-methyl-2-thioxo-1,3-thiazolidin-4-one (15) were prepared from 4-(1-methylethylidene)-2-phenyl-1,3-oxazol-5(4H)-one (2) and 5-(1-methylethylidene)-2-thioxo-1,3-thiazolidin-4-one (11), respectively. Treatment of compounds (3) and (15) with primary amines afforded 1,4-dihydropyridine derivatives (5) and (16) in 19-94% yields. Reactions of oxazoones (5) with hydrazine hydrate gave the corresponding imidazolones (6), while upon base- or acid catalysed methanolysis of 5 methyl (benzoylamino)(1-substituted pyridin-4(1H)-ylidene)acetates (7) were obtained. Catalytic hydrogenation of 7a furnished #alpha#-(piperidin-4-yl)glycine derivative (8) and/or #alpha#-(pyridin-2-yl)glycine derivative (9).