A Simple and Efficient Four-Component One-Pot Synthesis of Novel 2-Aryl-3-benzimidazolyl-3,4-dihydroimidazo[4,5-b]indoles Catalyzed by Ceric Ammonium Nitrate in Aqueous Ethanol

A simple and efficient protocol for the synthesis of benzimidazolylimidazo[4,5-b]indoles has been developed through the condensation of 2-aminobenzimidazole, aromatic aldehyde, ammonium acetate, and isatin via multicomponent reaction strategy using ceric ammonium nitrate as catalyst. The key advantages of the four-component reaction are easy work-up, high yield, short reaction time, and environmentally safe solvent.