One-Pot, Two-Step Synthesis of Imidazo[1,2‑a]benzimidazoles via A Multicomponent [4 + 1] Cycloaddition Reaction

A one-pot, two-step synthesis of imidazo­[1,2-a]­benzimidazoles has been achieved by a three-component reaction of 2-aminobenzimidazoles with an aromatic aldehyde and an isocyanide. The reaction involving condensation of 2-aminobenzimidazole with an aldehyde is run under microwave activation to generate an imine intermediate under basic conditions which then undergoes [4 + 1] cycloaddition with an isocyanide.