Reactions of 2-amino- and 2-hydrazinobenzimidazoles with 2-acyldimedones

The reaction of 2 formyldimedone with 2-amino- and 2-hydrazinobenzimidazoles at 20°C in ethanol gave 2-(2-benzimidazolyl)aminomethylene- and 2-2-(2-benzimidazolyl)hydrazinomethylene]-5,5-dimethylcylohex-anediones, while this reaction carried out in ethanol at reflux in the presence of acid gave 2,2-dimethyl-4-oxo 1, 2, 3, 4-tetrahydroquinazolino(1, 2-a]benzimidazole and 1-(2-benzimidazolyl)-6, 6-dimethyl-4-oxo-4, S, 6, 7-tetrahydroindazole, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 247–252, February, 1996.