Desvenlafaxine → Desvenlafaxine Fumarate

Participants

Reaction Conditions

Reaction Steps

To a 1000 ml flask equipped with a mechanical stirrer and condenser, O-Desmethyl venlafaxine base (50 g), fumaric acid (24.24 g), and isopropyl alcohol (IPA) (1000 ml) were added at room temperature to form a mixture. The mixture was then heated to reflux. A clear solution was obtained after filtering the heated mixture through a 1-micron filter. The filtered solution was cooled to 50° C., and then gradually cooled to 5° C. over five hrs. The cooled solution was stirred at 5° C. overnight. The mixture was then heated back to 50° C., stirred at 50° C. for 2 hrs, and then cooled back to 5° C. and stirred at 5° C. for 3 hrs. A solid precipitate formed and was filtered under reduced pressure, washed with IPA, and dried in a vacuum oven, overnight, at 50° C. The obtained solid was kept in a closed container at 4° C. for five weeks, after which Form N was obtained.

Provenance & Evidence