Patent ID: 6800759
Filing Date: 2004-10-05
Classification: A61K,C07D,Y02P

Abstract:
A process for preparing (S) clopidogrel bisulfate comprising the steps of:a) reacting a mixture of (R) and (S) clopidogrel free base with levorotatory camphor sulfonic acid in a C5 to a C12 hydrocarbon, optionally in a mixture with a suitable co-solvent, to precipitate (S) clopidogrel camphor sulfonate; b) converting (S) clopidogrel camphor sulfonate to clopidogrel base; c) preparing a solution of clopidogrel bisulfate from the clopidogrel base in an organic solvent; and d) recovering the clopidogrel bisulfate as a precipitate from the organic solvent.