Synthesis & anticonvulsant activity of some condensed imidazoles

Abstract

2-Mercapto-4,5-dihydroimidazole (la), 2-mercapto-3,4,5,6-tetrahydropyrimidine (lb) and 2-mer-_capto-3,4,5,6-tetrahydro-7H-l,3-diazepine (1c) react with methyl iodide to give the corresponding mercaptomethyl derivatives (2a-2c). Reaction of these mercaptomethyl compounds with aminoacetaldehyde diethyl acetal followed by treatment with hydrochloric acid affords lH-2,3-dihydroimidazo[l,2-a]imidazole (4), 5,6,7,8-tetrahydroimidazo[l,2-a]pyrimidine (19) and 9H-5,6,7, 8-tetrahydroimidazo[l,2-a]-[l,3]-diazepine (22), respectively. These condensed imidazoles have been reacted with aromatic acid chlorides, isocyanates and isothiocyanates. The structure and anticonvulsant activity of these compounds are described.