Originator
Prostetin,Takeda, Japan ,1981
Manufacturing Process
To a solution of 3.0 g of 16β-ethylestra-4-ene-3,17-dione dissolved in 150 ml of dioxane, are added 15 g of ethyl orthoformate and 0.1 g of ptoluenesulfonic acid, followed by stirring for 2 hours at room temperature. The reaction solution is poured into 300 ml of a 5% aqueous solution of sodium hydrogen carbonate and the resultant mixture is extracted with ether. The ether layer is washed with water and dried, followed by evaporation of the solvent to give crude crystals of 3-ethoxy-16β-ethylestra-3,5-diene-17-one. The crystals are recrystallized from ether to give 3.0 g of the compound melting at 114°C to 115°C
To a solution of 3.0 g of the enol-ether compound obtained above in 50 ml of methanol, is added 1.5 g of sodium borohydride. After standing for 1.5 hours at room temperature, the reaction solution is poured into 300 ml of water. The resulting precipitates are collected by filtration and recrystallized from ether to give 2.8 g of 3-ethoxy-16β-ethylestra-3,5-dien-17β-ol melting at 131°C to 133°C.
To a solution of 2.5 g of 3-ethoxy-16β-ethylestra-3,5-diene-17β-ol dissolved in
50 ml of methanol is added 1.2 ml of concentrated hydrochloric acid, followed by stirring for 10 minutes. The reaction solution is poured into 250 ml of water. The precipitated crystals are collected by filtration and recrystallized from ether to give 2.3 g of 16β-ethyl-17β-hydroxyestra-4-en-one melting at 152°C to 153°C.
