PROCESS FOR THE PREPARATION OF CHIRALLY PURE “H” NATEGLINIDE

摘要

The invention relates to N-(trans-4-isopropylcyclohexylcarbonyl)-D-phenylalanine (nateglinide) in the novel crystalline form "G" and a process for the preparation thereof. A process for the preparation of chirally pure nateglinide by treating a lower alkyl ester thereof with a base to yield an alkali salt and liberating the product from said salt by proper addition of an acid, is also provided. Still another aspect of the invention is a process for the preparation of nateglinide in the crystalline form "H" from other crystalline modifications of nateglinide.