Iodine-ammonium acetate promoted reaction between 2-aminopyridine and aryl methyl ketones: a novel approach towards the synthesis of 2-arylimidazo[1,2-a]pyridines

摘要

I-2-NH4OAc was found to be an efficient system for the metal-free synthesis of diversely substituted imidazo[1,2-a]pyridines 3a-r from 2-aminopyridine 1 and aryl methyl ketones 2a-r in one pot. 2-Arylimidazo[1,2-a]pyridines 3a-r were obtained in good to excellent yields via in situ generation of an Ortoleva-King intermediate (pyridinium iodide), followed by NH4OAc-assisted cyclization. (C) 2016 Elsevier Ltd. All rights reserved.