Methanesulfonic Acid → Taprizosin mesylate

Participants

Reaction Conditions

Reaction Steps

Under nitrogen, a suspension of Form B 4-amino-6,7-dimethoxy-2-(5-methanesulfonamido-1,2,3,4-tetrahydroisoquinol-2-yl)-5-(2-pyridyl)quinazoline (2.0 g) in butanone/water (10/1 by volume, 24 ml) was heated to reflux over 20 mins. Butanone/water 10/1 was added until a solution was achieved (an extra 3 ml was added, bringing the total solvent volume to 27 ml). The solution was left to cool to 50° C. and methanesulfonic acid (0.38 g, 4.0 mmol) was added dropwise over 30 seconds. The addition vessel was washed with butanone/water 10/1 (2×0.25 ml) and the washings were added to the reaction vessel. The resulting suspension was left to cool to room temperature and then stirred at this temperature for 2 h. The solid was collected by filtration, washed with acetone (2×2 ml), left to pull dry for 30 min and dried overnight in vacuo at 54° C. to afford the title compound (2.2 g) as a white solid.

Provenance & Evidence