反应详情

To a solution of 2.0 parts of 7-chloro-2-hydrazino-5-phenyl-3H-1,4-benzodiazepine and 7.4 parts of ethyl orthoformate in 80 parts by volume of chloroform is added 2 parts of concentrated sulfuric acid with stirring. The mixture is stirred at room temperature for further 30 minutes, and neutralized with a saturated aqueous sodium bicarbonate solution. Chloroform layer is washed with water and dried over sodium sulfate, followed by distillation of the solvent. Recrystallization of the residue from acetone-n-hexane yields 8-chloro-6-phenyl-4H-s-triazolo-[4,3-a][1,4]benzodiazepine as colorless flakes melting at 226°-227° C.

1. stirringThe mixture is stirred at room temperature for further 30 minutes
2. washChloroform layer is washed with water
3. dry with materialdried over sodium sulfate
4. distillationfollowed by distillation of the solvent
5. customRecrystallization of the residue from acetone-n-hexane