Sulfuric Acid → HCID 20317274, compound

Participants

Reaction Steps

To a suspension of 1.6 parts of 7-chloro-2-hydrazino-5-(p-methoxyphenyl)-3H-1,4-benzodiazepine prepared in Example 2 in 50 parts by volume of ethanol is added 3.0 parts of ethyl orthoformate, and then 0.5 part by volume of concentrated sulfuric acid is added dropwise with stirring. The whole mixture is stirred for a while and then neutralized with an aqueous slution of sodium bicarbonate, followed by evaporaton of the solvent. Water is added to the residue, whereby 8-chloro-6-(p-methoxyphenyl)-4H-s-triazolo (4,3-a) (1,4) benzodiazepine is yielded as crystals. Recrystallization from acetone and and then from ethyl acetate yields pale yellow flakes melting at 216° C to 217° C.

Provenance & Evidence