Reaktion #42650

Reaktionsgleichung

(11β,16β)-9-fluoro-11,17-dihydroxy-16-methyl-3,20-dioxopregna-1,4-dien-21-yl acetate

imidazole

trimethylsilyl chloride

→

title compound

Ausbeute 103.9%

(11β,16β)-9-fluoro-16-methyl-3,20-dioxo-11,17-bis[(trimethylsilyl)oxy]pregna-1,4-dien-21-yl acetate

Ausbeute 103.9%

Lösungsmittel

N,N-dimethylformamide

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenwashed successively with water, sat. NH4Cl, water, sat. NaHCO3, water, and brine
2. 2
   TrocknenThe organic phase was dried over Na2SO4
3. 3
   Filtrationfiltered
4. 4
   Sonstigeevaporated in vacuo

Vorschrift

To a solution of (11β,16β)-9-fluoro-11,17-dihydroxy-16-methyl-3,20-dioxopregna-1,4-dien-21-yl acetate (18.79 g, 43.25 mmol) and imidazole (58.89 g, 864.9 mmol) in 200 mL of dry N,N-dimethylformamide was added neat trimethylsilyl chloride (55.0 mL, 433 mmol) dropwise during 15 min. The resulting pale yellow solution was stirred at room temperature for 16 hours. The solution was diluted with ethyl acetate and washed successively with water, sat. NH4Cl, water, sat. NaHCO3, water, and brine. The organic phase was dried over Na2SO4, filtered and evaporated in vacuo to yield 26 g of the title compound as a pale yellow oil.

Quelle