Sulfuric Acid → Clopidogrel Bisulfate

Participants

Reaction Steps

Clopidogrel base (2.91 g) was dissolved in isopropanol (IPA) (44 ml). Ninety eight percent aqueous sulfuric acid (0.32 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 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 26 hours to obtain 3.04 g (80%) of clopidogrel hydrogensulfate crystal Form IV.

Provenance & Evidence