Crystalline 1&agr;-hydroxyvitamin D2 and method of purification thereof
US6432936B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 1999 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Jan 20, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C401/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method of purifying 1&agr;-hydroxyvitamin D2 to obtain 1&agr;-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&agr;-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&agr;-hydroxyvitamin D2 crystals, and recovering the 1&agr;-hydroxyvitamin D2 crystals. Optionally, petroleum ether may be added to the solvent after dissolving the product to be purified in the solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.