CRYSTALLINE 1.ALPHA.-HYDROXYVITAMIN D2 AND METHOD OF PURIFICATION THEREOF

摘要

A method of purifying 1.alpha.-hydroxyvitamin D2 to obtain 1.alpha.- hydroxyvitamin D2 in crystalline form. The method includes the steps of boiling a solvent selected from the group consisting of ethyl formate, ethyl acetate and a 2-propanol-hexane mixture under inert atmosphere, dissolving a product containing 1.alpha.-hydroxyvitamin D2 to be purified in the solvent, cooling the solvent and dissolved product below ambient temperature for a sufficient amount of time to form a precipitate of 1.alpha.-hydroxyvitamin D 2 crystals, and recovering the 1.alpha.-hydroxyvitamin D2 crystals. Optionally , petroleum ether may be added to the solvent after dissolving the product to be purified in the solvent.