An Efficient Copper‐Catalyzed Regioselective One‐Pot Synthesis of Pyrido[1,2‐a]benzimidazole and Its Derivatives

Abstract

AbstractA facile and effectual regioselective one‐pot synthesis protocol has been developed for the construction of pyrido[1,2‐a]benzimidazole and its derivatives using Copper(I) bromide as the catalyst, 1,10‐phenanthroline as ligand, and K3PO4 (Tripotassium phosphate) as the base in Dimethyl sulfoxide as solvent at 110 °C for 12 h. The reaction conditions were optimized by screening various copper catalysts, ligands, solvents, and bases. The substrate scope of the reaction was also carried out with electron‐withdrawing and donating functional groups to prepare novel functionalized regioselective benzimidazole compounds in good to excellent yields. All the isolated compounds were characterized by 1H, 13C, and 19F NMR.