Potassium Hydroxide → 3-Cyanoandrosta-3,5-diene-17beta-carboxylic acid

8.8 g of methyl 3-cyanoandrosta-3,5-diene-17β-carboxylate [prepared as described in step (a) above] and 4.3 g of potassium hydroxide were dissolved in a mixture of 20 ml of water and 200 ml of methanol, and the resulting solution was heated under reflux for 10 hours. At the end of this time, the methanol in the reaction mixture was removed by distillation under reduced pressure, the mixture was made acidic by the addition of dilute aqueous hydrochloric acid and extracted three times with methylene chloride. The organic extract was washed with water and then with a saturated aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate. In was then concentrated by evaporation under reduced pressure. The resulting residue was subjected to column chromatography through 150 g of silica gel using a gradient elution method, with mixtures of acetone and methylene chloride in ratios ranging from 2:98 to 16:84 by volume as the eluent, to give 7.1 g of the title compound.

1. temperaturethe resulting solution was heated
2. temperatureunder reflux for 10 hours
3. customAt the end of this time, the methanol in the reaction mixture was removed by distillation under reduced pressure
4. additionthe mixture was made acidic by the addition of dilute aqueous hydrochloric acid
5. extractionextracted three times with methylene chloride
6. extractionThe organic extract
7. washwas washed with water
8. dry with materialwith a saturated aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate
9. concentrationIn was then concentrated by evaporation under reduced pressure
10. washa gradient elution method

ORD-Eintrag

ord-581fc473c69d4daeb05469246eb0f68d

Quelldatensatz

uspto-grants-1997_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05698720