Process for the manufacture of benzodiazepine derivatives

Abstract From the Canadian patent

Benzodiazepine derivatives of formula I, wherein R signifies hydrogen or alkyl R1 signifies hydrogen, halogen or trifluoromethyl and R2 signifies phenyl, halophenyl or pyridyl and 4-oxides thereof are prepared by a novel process which comprises reacting a benzophenone of the general formula II, wherein R, R1 and R2 are as defined above with a nitroacetic acid halide, reducing the abtained nitroacetyl compound of the general formula III, wherein R, R1 and R2 are as defined above to the corresponding hydroxylamine or amine derivative and cyclizing the product thus obtained. Benzodiazepines of formula I and 4-oxides thereof are known compounds which are known to be useful as sedatives …