Water → Warfarin Potassium

Participants

Reaction Steps

Warfarin potassium salt is prepared by refluxing the pure warfarin acid with an equivalent amount or an excess of potassium carbonate in 2-propanol. The 2-propanol may be anhydrous or may contain about 0.5% to about 10% water, preferably about 1% to about 3% water. The molar ratio of potassium carbonate to warfarin acid is between about 0.9 and about 2, and is preferably between about 1.0 and about 1.3. The reaction may be conducted at a temperature ranging from room temperature to the boiling point of the solvent for a time of from about 1 hour to about 5 hours. Preferably, the reaction is conducted at reflux temperature and the preferred reaction time is from about 2 hours to about 3 hours. The unreacted carbonate is removed by filtration. The warfarin potassium is precipitated and isolated as a pure crystalline solid by filtration and drying.

Provenance & Evidence