反应详情

20 g of 11β-fluoro-7α-(5-hydroxypentyl)-estr-4-ene-3,17-dione in 100 ml of pyridine can be reacted over a period of 2 hours with 50 ml of acetic anhydride at 25° C. Then, 5 ml of water is added at 0° C., and it is stirred for 45 minutes. It is extracted with diethyl ether, washed with 2N sulfuric acid, pyridine-free, and the solution is neutralized in succession with saturated sodium bicarbonate solution and water. After drying and concentration by evaporation in a vacuum, the crude product is chromatographed on silica gel with a hexane-ethyl acetate-gradient. 17 g of 7α-(5-acetoxypentyl)-11β-fluoro-estr-4-ene-3,17-dione with a melting point of 78.4° C. is obtained.

1. extractionIt is extracted with diethyl ether
2. washwashed with 2N sulfuric acid, pyridine-free
3. customAfter drying
4. concentrationconcentration
5. customby evaporation in a vacuum
6. customthe crude product is chromatographed on silica gel with a hexane-ethyl acetate-gradient