反应详情

To a suspension of 1.35 parts of 2-amino-7-chloro-5-phenyl-3H-1,4-benzodiazepine in 25 parts by volume of methanol are added 0.6 part of 2-methylimidazole hydrochloride and 6 parts by volume of 1 mole methanol solution of hydrazine hydrate. The mixture is stirred at room temperature for 1.5 hours, followed by addition of 4.8 parts of ethyl orthoacetate and 10 parts by volume of ethanol containing 10% hydrogen chloride. The mixture is refluxed for 30 minutes, followed by evaporation of the solvent. The residue is neutralized with saturated aqueous sodium bicarbonate and extracted with methylene chloride. The methylene chloride extract is washed with water and dried over sodium sulfate, followed by evaporation of the solvent. The residue is purified by means of silica gel column-chromatography to give 8-chloro-1-methyl-6-phenyl-4H-s-triazolo [4,3-a][1,4] benzodiazepine. Recrystallization from a mixture of acetone and n-hexane affords colorless needles. Melting point: 225° C to 226° C.

1. temperatureThe mixture is refluxed for 30 minutes
2. customfollowed by evaporation of the solvent
3. extractionextracted with methylene chloride
4. extractionThe methylene chloride extract
5. washis washed with water
6. dry with materialdried over sodium sulfate
7. customfollowed by evaporation of the solvent
8. customThe residue is purified by means of silica gel column-chromatography