Реакция #215040

Уравнение реакции

Sodium acetate

acetic anhydride

(11β,16α)-9-fluoro-11,16,17-trihydroxy-3,20-dioxopregna-1,4-dien-21-oic acid, methyl ester

p-toluene sulfonic acid hydrate

→

title compound

11β,16α,17-Triacetyloxy-9-fluoro-3,20-dioxopregna-1,4-dien-21-oic acid, methyl ester

Растворители

acetic acid

Условия реакции

Обработка

1. 1
   Другоеthe solution is evaporated in vacuo
2. 2
   workup.ADDITIONThe residue is diluted with water
3. 3
   Экстракцияextracted with chloroform
4. 4
   Экстракцияthe chloroform extract
5. 5
   Промывкаis washed with water
6. 6
   Сушкаdried (MgSO4)
7. 7
   Другоеevaporated to a solid
8. 8
   ДругоеThe solid is crystallized from ethyl acetate

Методика

A suspension of (11β,16α)-9-fluoro-11,16,17-trihydroxy-3,20-dioxopregna-1,4-dien-21-oic acid, methyl ester (150 mg) in a mixture of glacial acetic acid (5.0 ml) and acetic anhydride (5.0 ml) containing p-toluene sulfonic acid hydrate (150 mg) is stirred for 40 hours. Sodium acetate (300 mg) is added and the solution is evaporated in vacuo. The residue is diluted with water, extracted with chloroform and the chloroform extract is washed with water, dried (MgSO4) and evaporated to a solid. The solid is crystallized from ethyl acetate to afford the title compound (164 mg), melting point 317°-319° C. (dec.) (discoloration starts from ca. 280° C.).

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