Doxazosin → Doxazosin Mesylate

Beteiligte Stoffe

Reaktionsschritte

6.1 g of anhydrous methanesulfonic acid were added to a stirred mixture of 27.1 g of doxazosin, 54 ml of N-methyl-2-pyrrolidone and 250 ml of methanol in a 500 ml three-necked round-bottomed flask. During this, the internal temperature rose to 30° C., and a solution formed. After the addition of the methanesulfonic acid was complete, the reaction mixture was filtered into a second 500 ml three-necked round-bottomed flask, and the filtrate was stirred for 5 h. After completion of the stirring time, the resulting precipitate was filtered off with suction and washed 2× with 50 ml of methanol each time. 45 g of moist doxazosin mesylate (modification D) were obtained. This corresponds to 28.5 g of dry substance and a yield of 86.7%.

Herkunft & Nachweise