A Facile Route to Pyrrolo[3′,4′:3,4]pyrido[1,2-a]benzimidazoles, Novel Heterocyclic Derivatives

The title system derivatives were prepared in two steps. Thus the condensation of 2-benzimidazoleacetonitrile with ethyl 4-chloro-3-oxobutanoate led to the 3-chloromethyl-1,5-dihydro-1-oxopyrido[1,2-a]benzimidazole-4-carbonitrile. Further amination of the obtained chloronitrile with primary amines yielded 1-amino-2,3-dihydro-2-R-5H-pyrrolo[3′,4′:3,4]pyrido[1,2-a]benzimidazol-5-ones.