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.
提供了分离克洛匹多巴的对映体的过程,以及将一种克洛匹多巴的对映体转化为另一种克洛匹多巴的对映体。通过在烃或烃和共溶剂混合物(最好是
DMF:
甲苯)中结晶化(S)对映体作为
樟脑磺酸盐来分离对映体。然后,将(R)对映体通过与催化量的碱反应(最好是
叔丁醇根)进行消旋并回收利用。