Sulfuric Acid → Alprazolam

Participants

Reaction Steps

To a suspension of 2.84 parts of 7-chloro-2-hydrazino-5-phenyl-3H-1,4-benzodiazepine in a mixture of 100 parts by volume of ethanol and 5 parts by volume of ethyl orthoacetate is added 1 part of concentrated sulfuric acid with stirring. The mixture is further stirred for 30 minutes, and about 100 parts by volume of a saturated aqueous sodium bicarbonate solution is added. The mixture is concentrated under reduced pressure. The resulting crystals are collected by filtration, washed with water and dried to give 8-chloro-1-methyl-6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepine as colorless crystals. Recrystallization from acetone-n-hexane gives colorless needles melting at 226°-227° C.

Provenance & Evidence