PROCESS FOR PREPARING OF PIOGLITAZONE HCL

摘要

A method for preparing HCl 5-{4-[2-(5-ethyl-pyridine-2-yl)-ethoxy]-benzyl}-thiazolidine-2,4-dione is provided to use a nitrobenzene derivative having a leaving group as a reaction intermediate which is a solid compound, does not generate a lot of impurities, and is easy for purification, thereby obtaining a desired product with high purity. A method for preparing pioglitazone HCl 5-(4-[2-(5-ethyl-pyridine-2-yl)-ethoxy]-benzyl)-thiazolidine-2,4-dione represented by the formula(1) comprises the steps of: (a) subjecting a nitrobenzene derivative represented by the formula(3) and having a leaving group(L) and 2-(5-ethyl-pyridine-2-yl)-ethanol represented by the formula(4) in the presence of a base such as sodium hydride or sodium hydroxide to a coupling reaction to obtain a 5-ethyl-2-[2-(4-nitrophenoxy)-ethyl]-pyridine compound represented by the formula(5); and (b) reducing the compound of the formula(5) to prepare 4-[2-(5-ethyl-pyridine-2-yl)-ethoxy]-phenylamine represented by the formula(6), wherein the leaving group is methanesulfonyloxy or p-toluene sulfonyloxy.