Patent ID: 6111142
Filing Date: 2000-08-29
Classification: C07C

Abstract:
A process for the purification of isoserinol to obtain products with a content in organic impurities <0.1% and in inorganic impurities lower than 0.05%, comprising the following steps:a) extraction of isoserinol using either esters of acetic acid with (C.sub.1 -C.sub.5) straight or branched alcohols or alcohol solvents of formula Alc--OH wherein Alc is a (C.sub.3 -C.sub.7) straight or branched chain;b) formation of the salts of isoserinol with an acid selected from the group consisting of: oxalic acid, an X--Ph--COOH acid, wherein X is a substituent at the phenyl ring Ph such as H, Cl, NO.sub.2, Br and (C.sub.1 -C.sub.4) straight or branched alkyl, or p-toluenesulfonic acid;c) crystallization of the salt formed in step b), using alcohol solvents of formula R--OH, wherein R is a (C.sub.1 -C.sub.6) straight or branched alkyl, or monoalkylether glycols of the class of (C.sub.3 -C.sub.7) alkylcellosolves, with water contents from 0.5% to 60%, depending on the used solvent;d) release and purification from the salt by use of ion exchange resins, to give compound of formula (I) as the free base;e) purification of the free base by crystallization using alcohols of formula R--OH.