A facile synthesis of pyrrolo[1,2-a]benzimidazole-fused pyrrole skeletons via a one-pot five-component reaction

In this study, an efficient and straightforward five-component protocol has been developed to synthesize the highly substituted novel class of pyrrolo[1,2- a ]benzimidazole skeleton which is fused with pyrrole rings. Starting materials including benzene-1,2-diamine, ethyl cyanoacetate, and aryl glyoxal in the presence of catalytic amount of piperidine as catalyst under refluxing ethanol is used for desired products. The sequence of cascade reactions includes Knoevenagel condensation, nucleophilic addition, Michael addition, and cyclization. • One-pot five-component reaction. • the synthesis of new heterocyclic compounds. • Synthesis the highly substituted novel class of pyrrolo[1,2- a ]benzimidazole skeleton which is fused with pyrrole rings. • The products described in this article have two important biological active moieties. • The biological evaluations of these derivatives are underway.