A Novel Reductive Cross-coupling Reaction of 2-nitrobenzoic Hydrazides and Aldehydes or Ketones Promoted by the Low-valence Titanium Reagent: An Access to 2,3,4,5-tetrahydro-1H-1,3,4-benzotriazepine-5-one Derivatives

Abstract

A short and facile synthesis of a series of 2,3,4,5-tetrahydro-1H-1,3,4-benzotriazepine-5-one derivatives was accomplished in good yields via the intermolecular reductive coupling reaction of 2-nitrobenzoic hydrazides and aldehydes or ketones promoted by the low-valence titanium reagent (TiCl₄/Zn system). Structures were established on the basis of elemental analysis, IR and ¹H NMR spectra.