Patent ID: 6432936
Filing Date: 2002-08-13
Classification: C07C

Abstract:
A method of purifying 1&agr;-hydroxyvitamin D2, comprising the steps of:(a) boiling a solvent consisting essentially of ethyl formate under inert atmosphere; (b) dissolving a product containing 1&agr;-hydroxyvitamin D2 to be purified in said solvent; (c) cooling said solvent and dissolved product below ambient temperature for a sufficient amount of time to form a precipitate of 1&agr;-hydroxyvitamin D2 crystals; and (d) recovering the 1&agr;-hydroxyvitamin D2 crystals having a molecular packing arrangement defined by space group C2 and unit cell dimensions a=23.9AÂ°, b=6.8AÂ°, c=17.9AÂ°, &agr;=90Â°, &bgr;=119.5Â° and &ggr;=90Â°.