Process for preparing .DELTA.9,11 and 21-chloro corticosteroids
US5616742A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1995 |
| Grant date | Apr 1, 1997 |
| Priority date | — |
| Expiry date | May 22, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07J51/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Described is a process for the regioselective dehydration of 11-hydroxy steroids using PCl.sub.5, PCl.sub.3, POCl.sub.3 or either SO.sub.2 Cl.sub.2 and imidazole, or PPh.sub.3 and CCl.sub.4. The disclosed process selectively forms .DELTA..sup.9,11 steroids from either 11-.alpha.- or 11-.beta.-hydroxy steroids, and can also be used for the one-step conversion of 11,21-dihydroxy steroids to 21-chloro-.DELTA..sup.9,11 steroids. Also disclosed are processes for the regioselective conversion of 11-.beta.-chloro steroids to .DELTA..sup.9,11 steroids, and for regioselectively converting an 11,17,21-trihydroxy streoid to a 21-chloro-11,17-dihydroxy steroid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.