Oxalic Acid → HCID 15307269, compound

Participants

Reaction Steps

A suspension of 1.2 g of 17-difluoromethylene-11β-methoxy-3-tetrahydropyranyloxy-estra-1,3,5(10)-triene in 25 ml of methanol and 2.6 ml of water is refluxed with 1.2 g of oxalic acid for 0.5 hour at a bath temperature of 100° C. Then, it is concentrated by evaporation in a vacuum diluted with ethyl acetate, washed with water, sodium bicarbonate solution as well as with saturated sodium chloride solution, dried on sodium sulfate, concentrated by evaporation in a vacuum and chromatographed on silica gel with hexane/acetone. After crystallization from hexane, 0.9 g of 17-difluoromethylene-11β-methoxy-estra-1,3,5(10)-trien-3-ol is obtained as colorless crystals with a melting point of 245-247° C., [α]D22 +77.3° (c=0.535% in pyridine).

Provenance & Evidence