Réaction #42652

Équation de réaction

t-butyl methyl ether hexane chloroform

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

ethyl isocyanate

→

title compound

Rendement 62.5%

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

Rendement 62.5%

Solvants

toluene

Conditions de réaction

Traitement

1. 1
   Températurethe mixture was refluxed for 48 hours
2. 2
   Autreevaporated under vacuum
3. 3
   Autreto leave a slightly gummy solid

Mode opératoire

To a mixture of (11β,16β)-9-fluoro-17-hydroxy-16-methyl-3,20-dioxo-11-[(trimethyl-silyl)oxy]-pregna-1,4-dien-21-yl acetate (3.11 g, 6.15 mmol) in 41 mL of toluene was added neat ethyl isocyanate (20.5 mL, 259 mmol) and the mixture was refluxed for 48 hours. The resulting solution was cooled to room temperature and evaporated under vacuum to leave a slightly gummy solid. Flash chromatography through a 1 kg column of silica gel eluting with t-butyl methyl ether/hexane/chloroform (1:1:1) gave 2.22 g of the title compound as a white solid.

Source