Patents Represented by Attorney, Agent or Law Firm Kenyon & Kenyoh
  • Racemization and enantiomer separation of clopidogrel
    Patent number: 6800759
    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.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: October 5, 2004
    Assignee: Teva Pharmaceutical Industries Ltd.
    Inventors: Merli Valeriano, Paola Daverio, Stefano Bianchi