Process for preparation of substantially pure glimepiride

摘要

The present invention discloses a novel process for purification of trans-4-methyl cyclohexylamine HCl and 4[-2-(3-Ethyl-4-methyl-2-carbonyl pyrrolidine amido) ethyl] benzene sulfonamide used in the synthesis of 3-Ethyl-2,5-dihydro-4-methyl-N-[2-[4-[[[[(trans-4-methyl cyclohexyl)amino]carbonyl]amino]sulfonyl]phenyl]ethyl]-2-oxo-1H-pyrrole-1-carboxamide (I), popularly known as Glimepiride. The present invention also discloses a novel purification of Glimepiride usingS methanolic ammonia and glacial acetic acid to obtain highly pure Glimepiride Form I (I) having the undesired cis isomer below 0.15%. Glimepiride (I) is useful in the treatment of diabetes mellitus.