A PROCESS FOR THE PREPARATION OF FEBUXOSTAT INTERMEDIATES

摘要

A process for the preparation of febuxostat is disclosed using specific content of phosphorus pentoxide in methanesulfonic acid (Eaton"s reagent). 2-(3-formyl-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid ethyl ester of formula (3), is a key intermediate for the process of the present invention. An object of the present invention is to provide an improved route for the synthesis of compound of formula (3) by using specific equivalents of phosphorous pentoxide in methanesulfonic acid and HMTA for formylation of 2-(4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid ethyl ester.