Copper-Catalyzed Synthesis of Imidazo[1,2-a]pyridines through Tandem Imine Formation-Oxidative Cyclization under Ambient Air: One-Step Synthesis of Zolimidine on a Gram-Scale

A new copper-catalyzed oxidative cyclization via CH amination between 2-aminopyridines and methyl aryl/heteroaryl ketones has been developed under ambient air. Imidazo[1,2-a]pyridines containing a wide range of functional groups have been synthesized from basic and easily available starting materials. This simple, one-pot reaction protocol is applicable for the direct preparation of zolimidine (a marketed antiulcer drug) on a large scale.