The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Oct. 05, 2004

Filed:

Mar. 19, 2003
Applicant:
Inventors:

Merli Valeriano, Cremella Lecco, IT;

Paola Daverio, Milan, IT;

Stefano Bianchi, Breccia Como, IT;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D 4/702 ; C07D / ;
U.S. Cl.
CPC ...
C07D 4/702 ; C07D / ;
Abstract

Processes for separation of enantiomers of clopidogrel, and converting one enantiomer of clopidogrel to another enantiomer of clopidogrel are provided. The enantiomers are separated by crystallizing the (S) enantiomer as camphor sulfonate salt from a hydrocarbon, or a mixture of a hydrocarbon and a co-solvent, preferably DMF:toluene. The (R) enantiomer is then racemized and recycled by reaction with a catalytic amount of a base, preferably with t-butoxide.


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