1,3-Dibromo-5,5-dimethylhydantoin → 11beta-Fluoroestra-4,6-diene-3,17-dione

Participants

Reaction Conditions

Reaction Steps

5 ml of a 10% by weight sodium acetate solution and, in portions, 2.5 g of 1,3-dibromo-5,5-dimethylhydantoin were added in succession at 0° C. to 5.0 g of 11β-fluoro-3-methoxy-estra-3,5-dien-17-one (A″) in 50 ml of DMF. After 30 minutes, 2.3 g of sodium sulfite and then 2.5 g of lithium bromide and 2.0 g of lithium carbonate were added and stirred for 2 hours at 100° C. The reaction mixture was stirred into ice water. The precipitated product was suctioned off, dissolved in ethyl acetate, washed with water, dried and concentrated by evaporation in a vacuum. After recrystallization from ethyl acetate, 3.6 g of 11β-fluoro-estra-4,6-diene-3,17-dione (B) with a melting point of 198° C. was obtained.

Provenance & Evidence