Sulfuric Acid → Clopidogrel Bisulfate

Participants

Reaction Steps

Clopidogrel base (2.93 g) was dissolved in isopropanol (45 ml). Sixty percent aqueous sulfuric acid (0.99 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 an additional 2.5 hours to obtain a white precipitate. The solid was collected by filtration, washed with isopropanol (2×10 ml) and dried at 50° C. in a vacuum oven for 15 hours to obtain 2.22 g (58%) of clopidogrel hydrogensulfate crystal Form IV.

Provenance & Evidence