Patent ID: 6080879
Filing Date: 2000-06-27
Classification: C07C

Abstract:
A method of crystallizing a hexafluoro-vitamin D compound of Formula (3) ##STR9## comprising: wherein R represents ##STR10## R.sub.1 represents a hydrogen atom, alkyl group, hydroxy group, protected hydroxy group or alkoxy group;X represents straight, branched or cyclic hydrocarbon group, saturated or unsaturated, having 1-12 carbon atoms which may carry one or more substituents selected from, halogen, hydroxy, protected hydroxy, alkoxy or oxo groups;Y.sub.1 and Y.sub.2 represent hydrogen atoms or taken together represent an exocyclic methylene group .dbd.CH.sub.2 ;Z.sub.1 and Z.sub.2 which may be the same or different represent a hydrogen, alkyl, hydroxyl, protected hydroxyl or alkoxy group or taken together may represent an oxo group or .dbd.CR.sub.2 R.sub.3 where R.sub.2 and R.sub.3 together or individually represent a hydrogen atom, alkyl group, protected hydroxy group or alkoxy group;dissolving the Vitamin D compound in a solvent comprising a 1-6 carbon halogenated alkane solvent having 1-3 halogen atoms per alkane molecule and a 1-12 carbon atom hydrocarbon solvent, the volume ratio of halogenated alkane solvent to hydrocarbon solvent being in the range of from about 4:1 to about 1:4 and thereafter crystallizing the Vitamin D compound.