Claims
- 1. A process for preparing the compound (11β,16β)-21-(3-carboxy-1-oxopropoxy)-11-hydroxy-2′-methyl-5′H-pregna-1,4-dieno(17,16-d)oxazole-3,20-dione of Formula I which comprises(a) reacting the compound (11β,16β)-11,21-dihydroxy-2′-methyl-5′H-pregna-1,4-dieno(17,16-d)oxazole-3,20-dione of Formula II with succinic anhydride in a (C1-C4) alkyl ester of a (C1-C4)carboxylic acid as the solvent, in the presence of a basic catalyst, (b) washing the obtained reaction mixture with an aqueous acid solution at a pH of about 2.0-3.5, and (c) separating the organic phase, filtering and concentrating the reaction mixture to a small volume to precipitate the compound of Formula I.
- 2. The process according to claim 1 wherein the solvent is ethyl acetate.
- 3. The process according to claim 1 or 2 wherein the basic catalyst is selected from the group consisting of trimethylamine, triethylamine, N-methyl-pyrrolidine, pyridine, 4-(N,N-dimethylamino)pyridine, 4-(N,N-diethylamino)pyridine, collidine, and picoline.
- 4. The process according to claim 1 or 2 wherein the basic catalyst is triethylamine.
- 5. The process according to claim 1 wherein the reaction temperature is from 0° C. to 60° C.
- 6. The process according to claim 1 wherein the reaction temperature is from 15° C. to 35° C.
- 7. The process according to claim 1 wherein the molar ratio between the compound of Formula II and succinic anhydride is from 1:2 to 1:5.
- 8. The process according to claim 1 wherein the molar ratio between the compound of Formula II and succinic anhydride is about 1:2.5.
- 9. The process according to claim 1 wherein the amount of basic catalyst is from 0.1 to 3 times the molar amount of the compound of Formula II.
- 10. The process according to claim 1 wherein the amount of basic catalyst is from equimolar to 2 times the molar amount of the compound of Formula II.
- 11. The process according to claim 1 wherein the aqueous acid solution is a solution of a diluted mineral acid.
Priority Claims (1)
Number |
Date |
Country |
Kind |
95119627 |
Dec 1995 |
EP |
|
Parent Case Info
This application is a continuation of application Ser. No. 09/077,729, now abandoned, which is a national stage entry under 35 U.S.C. §371 of PCT/EP96/05391, filed Dec. 4, 1996.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4440764 |
Nathansohn et al. |
Apr 1984 |
A |
Continuations (1)
|
Number |
Date |
Country |
Parent |
09/077729 |
|
US |
Child |
09/488035 |
|
US |