1, 4, 5, 6-Tetrahydropyrrolo [3, 4-b] pyridin-7-ones (III) and 2, 5, 5, 7, 7-pentamethyl-1, 4, 5, 7-tetrahydrofuro [3, 4-b] pyridines (XII) were synthesized from 4-benzylidene-2, 3-dioxopyrrolidines (I) or 4-benzylidene-2, 2, 5, 5-tetramethyltetrahydrofuran-3-ones (XI), respectively, to find new cardiovascular drugs. Their 1, 4-dihydropyridine structures were confirmed from spectral data and by oxidation to the corresponding pyridines. It was also found that Madhav's intermediate was not 1, 4-dihydropyridine (III) but 4-(3-amino-2-ethoxycarbonyl-1-phenyl-2-butenyl)-2, 3-dioxopyrrolidine (II1). 1, 4, 5, 6-Tetrahydropyrrolo [3, 4-b]-pyridin-7-ones possessing 6-ω-aminoalkyl substituent (VII) were obtained from 6-ω-hydroxyalkyl derivatives (V) by the usual way. These compounds were tested for coronary vasodilating and antihypertensive activities, and several of them showed a marked coronary vasodilating activity.
