Direct one-pot synthesis of zolimidine pharmaceutical drug and imidazo[1,2-a]pyridine derivatives via I2/CuO-promoted tandem strategy

An efficient one-pot synthetic protocol was developed for the synthesis of imidazo[1,2-a]pyridines from easily available starting materials: Aromatic ketones, alpha,beta-unsaturated ketones, beta-keto esters and 2-aminopyridines. The present reaction proceeded well in MeOH under the media of I-2/CuO. By using this method, the marketed drug zolimidine could be prepared easily with 95% yield. All these target products were characterized by NMR, HRMS and IR spectra. Furthermore, the target compound 3fa was determined by X-ray crystallographic analysis. (C) 2014 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.