Sumitomo Chemical Company, Limited

Tadashi Okamoto

Hisao Yamamoto

Shigeho Inaba

Kikuo Ishizumi

Kazuo Mori

Michihiro Yamamoto

Isamu Maruyama

Toshiyuki Hirohashi

Mitsuhiro Akatsu

Tsuyoshi Kobayashi

Yoshiharu Kume

Takahiro Izumi

Takeshi Akase

1,4-Benzodiazepine derivatives of the formula, ##STR1## wherein R.sub.1 is hydrogen, a lower alkyl, a haloalkyl, a cycloalkylalkyl, an alkoxyalkyl, an acyloxyalkyl, an alkylthioalkyl, an alkylaminoalkyl, a dialkylaminoalkyl, a hydroxyalkyl, carbamoyl, or an N-alkylcarbamoyl; R.sub.2 is hydrogen or a lower alkyl; X is hydrogen, a halogen, nitro, or trifluoromethyl; A is a group of the formula, ##STR2## (wherein Y and Z each represent hydrogen, a halogen, a lower alkyl, or nitro) and a salt thereof, are prepared by reacting a 1,4-benzodiazepin-2-one compound of the formula, ##STR3## wherein R.sub.1, R.sub.2, X, Y and Z are the same as defined above, with diborane in an inert solvent.

Process for preparing 1,4-benzodiazepines

A 1-alkyl-1,2,4,5-tetrahydro-3H-1,4-benzodiazepine derivative is produced by contacting a 1-aminoethyl-indole derivative with a suitable oxidizing agent and then reducing the resulting 1-acyl-2,3-dihydro-1H-1,4-benzodiazepine derivative. The starting 1-aminoethyl-indole derivative is prepared by subjecting a 3-phenyl-indole derivative to cyanomethylation (or carbamoylemethylation) and then reducing the resulting 1-cyanomethyl- (or 1-carbamoylmethyl)-indole derivative. The 1-acyl-1,2,4,5-tetrahydro-3H-1,4-benzodiazepine derivative is useful as a tranquillizer, muscle-relaxant, etc.

Preparation of benzodiazepines

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Ashiya, Japan

Tadashi Okamoto