Potential hypnotics and anxiolytics in the 4H-s-triazolo[4,3-a]-1,4-benzodiazepine series: 8-Chloro-6-(2-chlorophenyl)-1-[4-(2-methoxyethyl)piperazino]-4H-s-triazolo[4,3-a]-1,4-benzodiazepine and some related compounds

Abstract

1-Bromo derivatives XIIa and XIIb were prepared by bromination of 8-chloro-6-phenyl-4H-s-triazolo[4,3-a]-1,4-benzodiazepine (XIa) and its 6-(2-chlorophenyl) analogue XIb with bromine in chloroform in the presence of pyridine. Substitution reactions with 1-(2-methoxyethyl)piperazine (XIVb), 1-(3-methoxypropyl)piperazine (XVb), 1-(2-ethoxyethyl)piperazine (XVIb) and 1-(2-methylthioethyl)piperazine (XVIIb) afforded the title compound IIb and analogues IIa and IIIb-Vb. A substitution reaction of the bromo derivative XIIb with piperazine gave the 1-piperazino derivative VIIIb which was alkylated with 2-phenoxyethyl bromide and 2-phenylthioethyl bromide to give compounds VIb and VIIb. The title compound IIb has very high anticonvulsant and discoordinating activities in mice. The enlargement of the substituent R1 (compounds IIIb-VIIb) results in a gradual decrease of the effects mentioned.