Abstract
The first synthesis of 2-amino-α-phenylbenzylideneaminoacetonitriles (IV) was achieved by an amine exchange reaction between Schiff bases (II) and aminoacetonitrile hydrogensulfate (III) in the presence of 2-methylimidazole. Compounds (IV) were cyclized to 2-amino-1, 4-benzodiazepine derivatives (V) in a good yield using potassium hydroxide in ethanol or dry hydrogen chloride in methanol or ethanol. When an N-substituted analog of IV was emrloyed in this reaction, a new type of derivative, 2-imimo compound (VII), was obtained. Both V and VII were hydrolyzed easily and selectively to their corresponding 1, 4-benzodiazepin-2-ones when their acid salts were heated in methanol. Certain geometrical isomers of IV were isolated and their isomeric structure was determined by infrared, ultraviolet and nuclear magnetic resonance spectra. Similarly, 2-amino-7-chloro-5-methyl-3H-1, 4-benzodiazepine (XIII) was synthesized by cyclization of 2-amino-5-chloro-α-methylbenzylideneaminoacetonitrile (XII) with methanolic potassium hydroxide.
