Sanofi Synthesis of (±) Clopidogrel

RPG Synthesis of (±) Clopidogrel

It is interesting to note that only the enantiomerically pure (+)-clopidogrel (dextrorotatory, rotates plane polarised light in a clockwise direction) exhibits platelet aggregation inhibiting activity while the (-)- clopidogrel (levorotatory, rotates plane polarised light in an anticlockwise direction) is inactive. Enantiomerically pure (+) clopidogrel used to be obtained from resolution of the racemic clopidogrel. If racemic clopidogrel is mixed with levorotatory camphor-10-sulfonic acid in acetone then a salt is obtained which can be recrystallised from acetone to generate (+)-clopidogrel

Asymmetric synthesis of (+)- clopidogrel

Syntheses taken from J.Li, et al, Contemporary Drug Synthesis, Wiley Interscience, 2004.