19-Mercaptoandrost-4-ene-3,17-dione → 3-Fluoromethylene-19-mercapto-4-androsten-17-one

Participants

Reaction Conditions

Reaction Steps

17.2 g of fluoromethyl triphenylphosphonium tetrafluoroborate is suspended in 120 ml of tetrahydrofuran and mixed at 25° C. by portions with 7.8 g of potassium tert-butylate. Stirring is continued for one more hour, it is cooled to 0° C. and 1.5 g of 19-mercapto-4-androstene-3,17-dione (European patent 100,556) is instilled in 10 ml of tetrahydrofuran and stirring is continud for 30 more minutes. Then it is neutralized in 1N hydrochloric acid, the reaction mixture is added to waer, extracted 4 times with ethyl acetate, the organic phases washed neutral, dried on sodium sulfate and freed rom the solvent in a vacuum. After chromatography on silica gel with hexane/ethyl acetate, 752 mg of 3-fluoromethylene-19-mercapto-4-androsten-17-one with a melting point of 118°-120° C. is obtained.

Provenance & Evidence