Crystalline 1&agr;, 24(S)-dihydroxyvitamin D2 and method of purification thereof
US6362350B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1999 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Nov 10, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C401/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method of purifying 1&agr;,24(S)-dihydroxyvitamin D2 to obtain 1&agr;,24(S)-dihydroxyvitamin D2 in crystalline form. The method includes the steps of boiling a solvent under inert atmosphere, dissolving a product containing 1&agr;,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&agr;,24(S)-dihydroxyvitamin D2 crystals, and recovering the 1&agr;,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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.