Heterocyclic variants of the 1,5-benzodiazepine system. VIII. Reaction of 4(7)-aminobenzimidazole with ethyl 2-alkylmalonates

Reaction of 4(7)-aminobenzimidazole with ethyl 2-alkylmalonates gave the novel 4,5,6,7-tetrahydro-5-alkyl-imidazo[1,5,4-ef][1,5]benzodiazepine-4,6-diones, and the 2-alkyl-4(7)-(2′-ethoxycarbonyl)acetamido-benzimidazoles. The structure of all the products was corroborated by ir, mass spectrometry and ¹H-nmr.