Some Aspects of the Chemistry of Hydrazides and Thiohydrazides

Abstract

<p> In or der to study the mechanism of their conversio~ into hydrazides and thiohydrazides, a number of hydrazidic halides were treated with compounds containing a nucleophilic oxygen or sulfur atom. </p> <p> The initial products of these reactions were formed from the displacement of the (alpha)-halogen atom of the hydrazidic halide. In cases where there was sufficient activation the group attached to oxygen or sulfur was transferred to nitrogen in the presence of base. </p> <p> Some hydrazides and thiohydrazides containing displace-able groups in the 2-position of an N-aryl ring yielded benzoxadiazines and benzothiadiazines respectively under basic conditions. The reactions exhibited the characteristics of bimolecular nμcleophilic aromatic substitutions. The synthesis of four novel heterocyclic ring systems is described. </p>