Hydrazine hydrate (1:1) → 5H-2,3-Benzodiazepine-4-methanol, 1-(3-chlorophenyl)-7,8-dimethoxy-

Participants

Reaction Steps

6.7 g (17.3 mmoles) of 2-(3-acetoxyacetonyl)-3'-chloro-4,5-dimethoxybenzophenone [(IV), R=CH3 ] are suspended in 70 ml of 99.5% ethanol, then 5.2 l (104 mmoles) of 100% hydrazine hydrate are added under stirring. The reaction mixture is stirred at room temperature for 72 hours, treated with activated carbon, filtered and 82 ml of distilled water are added to the filtrate. Then 4 ml of glacial acetic acid are dropped to the pale yellow solution under cooling with ice-cold water. Upon scratching crystals get separated. The suspension is kept overnight at 1° to 5° C., filtered, washed five times with 5 ml of ice-cold 50% ethanol solution each and the product is dried at a temperature between 80° and 100° C. Thus 4.64 g of crude product are obtained.

Provenance & Evidence