Process for R-epimer enrichment of 16,17-acetal derivatives...

Details Process for R-epimer enrichment of 16,17-acetal derivatives... Process for R-epimer enrichment of 16,17-acetal derivatives...

1999-02-11

2004-09-07

Page, Thurman K. (Department: 1615)

Drug, bio-affecting and body treating compositions

Designated organic active ingredient containing

Cyclopentanohydrophenanthrene ring system doai

C540S063000

Reexamination Certificate

active

06787533

ABSTRACT:

FIELD OF THE INVENTION
The invention relates to a novel process for increasing the proportion of one epimer in epimer mixtures of certain pregna-1,4-diene-3,20-dione 16,17-acetal 21-esters.
PRIOR ART
DE-A 41 29 535 discloses epimeric pregna-1,4-diene-3,20-dione 16,17-acetal 21-esters with an antiinflammatory action. These have a butyl, isopropyl, sec-butyl, cyclohexyl or phenyl radical on the cyclic acetal ring, and their C-21 hydroxyl group is acylated by an acetyl or isobutyryl radical. The application describes how the respective R-epimer is obtained, starting from an R/S mixture, by preparative high-pressure liquid chromatography (HPLC). International Patent Application WO95/24416 describes a process for the epimer enrichment of pregna-1,4-diene-3,20-dione 16,17-acetal derivatives by silylation, fractional crystallization and acid hydrolysis.


REFERENCES:
patent: 3928326 (1975-12-01), Brattsand et al.
patent: 3992534 (1976-11-01), Brattsand et al.
patent: 3996359 (1976-12-01), Brattsand et al.
patent: 4036831 (1977-07-01), Loken et al.
patent: 4695625 (1987-09-01), MacDonald
patent: 4835145 (1989-05-01), MacDonald
patent: 5482934 (1996-01-01), Calatayud et al.
patent: 5482935 (1996-01-01), Adelman et al.
patent: 5728826 (1998-03-01), Gutterer
patent: 5733901 (1998-03-01), Gutterer
Linus Pauling (Genral Chemistry, W.H. Freeman and Company, San Francisco, California (1947), Chapter 2, p. 14, last para and p. 15 lines 1-2)., 1947.*
Acta Pharmaceutica Suecicia, vol. 24, pp. 97-114, (1987).

Affiliated with

Also associated with

Rating

Process for R-epimer enrichment of 16,17-acetal derivatives... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for R-epimer enrichment of 16,17-acetal derivatives..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for R-epimer enrichment of 16,17-acetal derivatives... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3227227