Oxalic Acid → HCID 15307276, compound

Participants

Reaction Steps

A suspension of 927 mg of 17-difluoromethylene-3-tetrahydropyranyloxy-estra-1,3,5(10),8-tetraene in 20 ml of methanol and 2.0 ml of water is refluxed with 950 mg 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 three times with water, once with sodium bicarbonate solution as well as with saturated sodium chloride solution, dried on sodium sulfate and concentrated by evaporation in a vacuum. After crystallization from hexane, 0.5 g of 17-difluoromethylene-estra-1,3,5(10),8-tetraen-3-ol is obtained as colorless crystals with a melting point of 127-128° C., [α]D22 =-1.5° (c=0.515% in pyridine).

Provenance & Evidence