Isopropanol → Desvenlafaxine Fumarate

Participants

Reaction Steps

In one specific embodiment, O-desmethylvenlafaxine, fumaric acid and the isopropyl alcohol or ethyl lactate solvent are combined to form a solution. Where the solvent is isopropyl alcohol, O-desmethylvenlafaxine and fumaric acid in the solvent may be heated to obtain a solution. Heating may be carried out from about room temperature to about reflux temperature of the solvent. The solution may than be cooled to a temperature of about 50° C. or less, preferably to about 15° C. to about 30° C., preferably to about room temperature. The solution is maintained for an overnight period, preferably about 8 hours to about 20 hours, more preferably for about 18 hours, at a temperature of about 15° C. to about 30° C., preferably room temperature, to obtain O-desmethylvenlafaxine fumarate crystal Form II. The reaction mixture may be stirred before, during or after precipitation.

Provenance & Evidence