17.0 g of copper(II) bromide is added to 27.8 g of 7α-(5-bromopentyl)-11β-fluor-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, and twice with ammonium chloride, washed 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.
