Sulfuric Acid → HCID 20317274, compound

Participants

Reaction Steps

To a solution of 1.6 parts of 7-chloro-2-hydrazino-5-(4-methoxyphenyl)-3H-1,4-benzodiazepine in 50 parts by volume of ethanol is added 3 parts of ethyl orthoformate. To the mixture is added 0.5 part by volume of concentrated sulfuric acid with stirring. After 5 minutes, the reaction mixture is neutralized with a saturated aqueous sodium bicarbonate solution, followed by removal of the solvent. To the residue is added water, whereupon 8-chloro-6-(4-methoxyphenyl)-4H-s-triazolo[4,3-a][1,4]benzodiazepine is obtained as crystals. Recrystallization from acetone-ethyl acetate gives pale yellow flakes melting at 216°-217° C.

Provenance & Evidence