PROCESS FOR PREPARING RHODANINE-3-ACETIC ACID: A KEY INTERMEDIATED OF EPALRESTAT

摘要

A process for preparation of (4-oxo-2-thioxo-1,3-thiazolidin-3-yl) acetic acid comprising: (a) reaction of compound of formula (VIII) wherein Y is Cl, Br, I, OTs, OMs and R is C_1-8 alkyl, benzyl, cycloalkyl, phenyl, substituted phenyl and their like; with a compound of formula (VIIIA) wherein M is K, Na or Li, preferably K; R₁ is C_1-4 alkyl, benzyl, C₁-C₈ cycloalkyl, phenyl and their like, in aqueous medium to give a compound of formula (IX) (b) cyclizing a compound of formula (IX) using a base to give a compound of formula (X) in a solvent. (c) hydrolyzing (X) using aqueous mineral acid.