Sulfuric Acid → Clopidogrel Bisulfate

Participants

Reaction Steps

Clopidogrel base (2.96 g) was dissolved in isopropanol (IPA) (45 mL). Eighty percent aqueous sulfuric acid (0.65 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 1.5 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 15 hours to obtain 3.24 g (84%) of clopidogrel hydrogensulfate crystal Form IV.

Provenance & Evidence