Oxalyl chloride → 17beta-Chlorocarbonyl-5alpha-androstan-3-one

Participants

Reaction Steps

A solution of 5α-androstan-3-one 17β-carboxylic acid (2.25 g., corrected for the presence of 15% 5α-pregnan-3,20-dione as an impurity) and oxalyl chloride (4.5 ml.) in dry benzene (150 ml.) was refluxed for 1.5 hours, and then evaporated to dryness to afford crude 17β-chlorocarbonyl-5α-androstan-3-one. This acid chloride in benzene (15 ml.) was shaken with 880 ammonia (24 ml.) and water (15 ml.) for 5 minutes. After a further 30 minutes of standing at room temperature the precipitated amide was filtered, washed with water and dried. Recrysyallisation from dichloromethane/petrol afforded title compound (1.18 g.) m.p. 259°-262°. A further recrystallisation from dichloromethane/petrol provided an analytically pure sample; m.p. 276°-277°; [α]D + 51.5°, (c 0.6%).

Provenance & Evidence