The invention belongs to the field of
organic chemistry, particularly relates to a method for recovering desogestrel recrystallization
mother liquor. In allusion to the problem that desogestrel cannot be further recovered through a common recrystallization method after the content ratio of a [
delta]3 isomer to desogestrel in the
crystallization mother liquor reaches 40: 60 in the prior art, the invention proposes the following scheme:
Side chain degradation, reduction, esterification, bromination,
elimination,
hydrolysis and Birch reduction are carried out on the recrystallized
mother liquor to obtain the desogestrel intermediate with a
single component. According to the invention, the desogestrel recrystallization mother liquor is converted into the single-component 18-methyl-11-
methylene-estra-4-ene-17beta-ol at high yield, the used main
raw material is the original waste mother liquor in desogestrel production, the high atom
utilization rate required by environment-friendly production is met, and the economic benefit is improved.