Sulfuric Acid → Clopidogrel Bisulfate

Participants

Reaction Steps

Clopidogrel base (2.85 g) was dissolved in isopropanol (43 mL). Forty percent aqueous sulfuric acid (1.67 mL) was added to the solution at 20° C. The reaction mixture was heated to reflux temperature for 2 hours. Then, the solution was cooled to room temperature and stirred at this temperature for additional 3.5 hours to obtain a white precipitate. The solid was collected by filtration, washed with IPA (2×10 ml) and dried at 50° C. in a vacuum oven for 14.5 hours to obtain 1.47 g (40%) of clopidogrel hydrogensulfate crystal Form IV.

Provenance & Evidence