Method for the isolation of 6&agr;, 9&agr;-difluoro-11&bgr;, 17&agr;-dihydroxy-16&agr;-methylpregna-3-oxo-1,4-diene-17&bgr;-carboxylic acid
US6747163B2 · kind B2 · utility
1Cited by
1References
4Claims
0Family size
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Key dates
| Filing date | Apr 4, 2003 |
| Grant date | Jun 8, 2004 |
| Priority date | — |
| Expiry date | Apr 4, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07J3/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention provides a process for the preparation and isolation of compound of formula 2, comprising the following steps: oxidizing Flumethasone dissolved in a tetrahydrofuran-water mixture with periodic acid at a temperature lower than 30° C.; cooling the reaction mixture to a temperature lower than 10° C.; adding an antisolvent precooled to a temperature lower than 10° C.; and separating the precipitated crystal by filtration, whereby there is obtained a compound of formula 2 in a yield of at least 98% and of a chromatographic purity of at least 99%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.