17.0 g of copper(II) bromide is added to 27.8 g of 7α-(5-bromopentyl)-11β-fluoro-estr-4-ene-3,17-dione in 190 ml of acetonitrile at 80° C. After 8 hours, the reaction mixture is stirred into water, extracted three times with ethyl acetate, washed twice with ammonium chloride, with sodium bicarbonate and common salt, dried and concentrated by evaporation in a vacuum. After the crude product is chromatographed on silica gel with a hexane-ethyl acetate gradient, 20.4 g of 7α-(5-bromopentyl)-11β-fluoro-3-hydroxy-estra-1,3,5(10)-trien-17-one is obtained as colorless crystals with a melting point of 178° C.
