Diloderm ,Schering,US,1960
A solution of 1.0 g of 1,4,9(11)-pregnatriene-17α,21-diol-3,20-dione-21-
acetate and 5.0 g of lithium chloride in 40 ml of glacial acetic acid is treated
with 0.410 g of N-chlorosuccinimide, followed by 0.104 g of anhydrous
hydrogen chloride dissolved in 2.5 ml of tetrahydrofuran. The reaction mixture
is stirred for 2 hours and poured into ice water. The crude product is filtered
and washed with water to give 1.12 g of solid material, which is recrystallized
from acetone-hexane to give substantially pure 9α,11β-dichloro-1,4-
pregnadiene-17α,21-diol-3,20-dione-21-acetate; MP 246°C to 253°C (dec.).
