PROCESS FOR PREPARING BEPOTASTINE AND INTERMEDIATES USED THEREIN

摘要

A process for stereospecific preparation of bepotastine of formula (I) and novel intermediates used therein having formulae (II) to (IV) are provided. The inventive process comprises subjecting (RS)-4-[(4-chlorophenyl)(2-pyridyl)methoxy]piperidine to a reaction with a 4-halobutanoic acid l-menthyl ester, halo being chloro, bromo or iodo, in an organic solvent in the presence of a base to produce (RS)-bepotastine l-menthyl ester of formula (II), conducting a reaction of the compound of formula (II) with N-benzyloxycarbonyl L-aspartic acid in an organic solvent to induce selective precipitation of bepotastine l-menthyl ester?N-benzyloxycarbonyl L-aspartate of formula (III), filtering the precipitates formed in step 2) to isolate the compound of formula (III), treating the compound of formula (III) with a base to liberate bepotastine l-menthyl ester of formula (IV), and hydrolyzing the compound of formula (IV) in the presence of a base. The inventive process can provide bepotastine having a high optical purity of not less than 99.5% in a high yield, and thus, is useful in the development of anti-histamines and anti-allergic agents.