Carbon tetrabromide → 7alpha-(5-Bromopentyl)-11beta-fluoro-estr-4-ene-3,17-dione

Participants

Reaction Steps

A solution of 33 g of 11β-fluoro-7α-(5-hydroxypentyl)oestr-4-ene-3,17-dione in 330 ml of dichloromethane is treated with 28.9 g of triphenylphosphine and 36.7 g of carbon tetrabromide at −5° C. and stirred for 0.5 hours. Dichloromethane is then added and the mixture is washed with water, saturated sodium hydrogencarbonate solution and sodium chloride solution. The organic phase is dried over sodium sulphate and concentrated in vacuo. The crude product is then chromatographed on silica gel using a hexane-ethyl acetate gradient. 28.5 g of 7α-(5-bromopentyl)-11β-fluorooestr-4-ene-3,17-dione of melting point 75-76° C. are obtained.

Provenance & Evidence