Patent ID: 7714133
Filing Date: 2010-05-11
Classification: A61P,C07D

Abstract:
1. A method for manufacturing hydrogen sulphate (alpha S) of the alpha-(2-chlorophenyl)-6,7-dihydro-thieno[3,2-c]pyridine-5(4H)-acetic acid methyl ester (clopidogrel hydrogen sulphate) of formula I in crystalline Form I, said method comprising separating crystalline Form I of the compound of formula I out of a solution of clopidogrel in the form of the free base in a solvent selected from the group consisting of 2-propanol and n-butyl acetate by adding 0.6 to 1.1 equivalent of sulphuric acid at 0 to −5° C. when 2-propanol is the solvent or at 0 to +5° C. when n-butylacetate is the solvent, and then stirring the mixture at a temperature between −5 and 15° C.