反应详情

A solution of 9-fluoro-11β-hydroxyandrosta-1,4-diene-3,17-dione (5.0 g) in a mixture of acetic acid (60 ml) and acetic anhydride (60 ml) containing p-toluenesulfonic acid (2.5 g) is maintained at room temperature for eighteen hours. Sodium acetate (2.5 g) is added and the mixture is concentrated in vacuo at 35°-40° C. The residue is diluted with water (150 ml) and the solid that separates is isolated by filtration, washed with water and dried in vacuo to afford the title compound as a solid (5.0 g) with consistent spectral data. An examination (silica gel, chloroform: ethyl acetate, 95:5) reveals the presence of a small amount of starting steroid as the only significant impurity. This material is used without purification in the next step. A specimen crystallized from acetone-hexane melts at 173°-174° C.

1. concentrationthe mixture is concentrated in vacuo at 35°-40° C
2. additionThe residue is diluted with water (150 ml)
3. customthe solid that separates is isolated by filtration
4. washwashed with water
5. customdried in vacuo