CRYSTALLINE 1 alpha ,24(S)-DIHYDROXYVITAMIN D2 AND METHOD OF PURIFICATION THEREOF

摘要

A method of purifying 1 alpha ,24(S)-dihydroxyvitamin D2 to obtain 1 alpha ,24(S)-dihydroxyvitamin D2 in crystalline form. The method includes the steps of boiling a solvent under inert atmosphere, dissolving a product containing 1 alpha ,24(S)-dihydroxyvitamin 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 ,24(S)-dihydroxyvitamin D2 crystals, and recovering the 1 alpha ,24(S)-dihydroxyvitamin D2 crystals. The purification technique involves using one of several binary solvent systems, namely, acetone and hexane, 2-propanol and hexane, or ethyl formate and petroleum ether.