(RS)-Clopidogrel → 2-chlorophenyl(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)acetic acid methyl ester (-)-camphorsulfonic acid salt

Participants

Reaction Steps

32 g (0.0994 mol) of (2-chlorophenyl)(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)acetic acid methyl ester is dissolved in 150 ml of acetone and to the solution 9.95 g (0.0397 mol) of laevorotatory 10-camphorsulfonic acid monohydrate is added. The homogenous reaction mixture is allowed to stay at room temperature. After 48 hours a few crystals appear. The mixture is concentrated by evaporation to 50 ml and allowed to stay at room temperature for 24 hours. The resulting crystals are filtered off, washed with acetone and dried. The crystals thus obtained are dissolved again in a very small amount (50 ml) of hot acetone and after cooling the crystals are filtered off, washed with acetone and dried. Thus the title compound is obtained. Yield: 88%. Mp.: 165° C. [α]20D=+24° (c=1.68 g/100 ml; methanol).

Provenance & Evidence