Manufacturing Process
To 6α-fluoro-16α-hydroxy-hydrocortisone 21-acetate, described by Mills et al,
J. Am. Chem. Soc., volume 81, pages 1264 to 1265, March 5, 1959, there
was added acetic anhydride in dry pyridine. The reaction mixture was left at
room temperature overnight and was then poured with stirring into ice water.
The resulting precipitate was filtered, washed with water and crystallized from
acetone-hexane to give 6α-fluoro-16α-hydroxy-hydrocortisone-16α,21-
diacetate. This was reacted with methane-sulfonyl chloride in dimethyl
formamide in the presence of pyridine at 80°C for 1 hour. The mixture was
cooled, diluted with water and extracted with ethyl acetate. The extract was
washed with water, dried over anhydrous sodium sulfate and the ethyl acetate
was evaporated. By recrystallization of the residue from acetone-hexane there
was obtained 6α-fluoro-Δ4,9(11)-pregnadiene-16α,17α,21-triol-3,20-dione-
16α,21-diacetate.
This was reacted with chlorine to give the dichloropregnene compound, then
with selenium dioxide to give the dichloropregnadiene compound. By
hydrolysis with methanolic potassium hydroxide there was obtained the free
6α-fluoro-9α,11β-dichloro-Δ1,4-pregnadiene-16α,17α,21-triol-3,20-dione. By
treatment with acetone in the presence of perchloric acid, the 16,17-acetonide
of 6α-fluoro-9α,11β-dichloro-Δ1,4-pregnadiene-16α,17α,21-triol-3,20-dione
was formed.
