反应详情

A solution of sodium hydroxide (1.1 g) in water (18 mL) was stirred at -5° C. and bromine (0.4 mL) was added very slowly. Cold dioxane (12 mL) was added and the resulting sodium hypobromite solution was added to a solution of 3α-hydroxy-5α-pregnane-20-one (0.6 g) in dioxane (30 mL) at 0° C. The resulting mixture was kept at this temperature for 1 hr., neutralized with concentrated hydrochloric acid and poured into water. Excess 2N hydrochloric acid was then added and the precipitated solid was collected by filtration and dried in vacuo which gave the title compound.

1. filtrationthe precipitated solid was collected by filtration
2. customdried in vacuo which