Process for the preparation of 7.alpha.-halogeno-3-oxo-4-dehydro steroids and novel 7.alpha.-halogeno derivatives produced thereby
US4076708A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1976 |
| Grant date | Feb 28, 1978 |
| Priority date | — |
| Expiry date | Dec 22, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07J21/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
3-Oxo-6-unsubstituted-7.alpha.-halogeno-4-dehydro steroids, wherein said halogen is chlorine, bromine or iodine, are prepared by reaction of a 3-oxo-6,7-di-unsubstituted-4,6-bis-dehydro steroid with at least an equimolar quantity of the corresponding hydrogen halide in a non-reactive organic solvent at temperatures no higher than about 30.degree. C, and then are isolated by removal of said solvent and any excess acid at temperatures no higher than about 25.degree. C without subjecting said 3-oxo-6-unsubstituted-7.alpha.-halogeno-4-dehydro steroid to a basic medium. A preferred species of this process is that wherein the starting steroid is a 3,20-dioxo-9-unsubstituted-11-oxygenated-1,4,6-pregnatriene-17,21-diol or ester thereof, preferably a 17,21-di-lower alkanoate or a 17-benzoate 21-lower alkanoate ester thereof, whereby is prepared in good yields a 3,20-dioxo-7.alpha.-halogeno-1,4-pregnadiene-17.alpha.,21-diol or ester thereof, useful as topical anti-inflammatory agents. Also described are novel 3,20-dioxo-7.alpha.-halogeno-4-pregnene-17.alpha.,21-diols and esters thereof having anti-inflammatory activity as well as 3-oxo-7.alpha.-halogeno-17.alpha.-4-pregnene-21,17.beta.-carbo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.