Doxazosin → Doxazosin Mesylate

Participants

Reaction Conditions

Reaction Steps

Doxazosin base (0.277 mol; 125 g) was charged in acetone (1875 ml) and stirred at 25° C. to obtain slurry. On cooling the slurry to 10-15° C., methanesulphonic acid (0.33 mol; 31.96 g) was added to it. The contents were stirred for 10-15 min at 10-15° C. and then stirring continued at 25° C. for 2 hr. The solid obtained was filtered, washed with acetone and dried at 50-55° C. to obtain solid. The solid was purified by refluxing in methanol (1500 ml) for 1 hr. The slurry was cooled to room temperature, filtered, washed with methanol and then dried at 60° C. under reduced pressure to obtain 135 g of pure doxazosin mesylate (HPLC purity −99.81%).

Provenance & Evidence