Heterocycles from Sulphamylphenylhydrazines. Part I. 2-(p-Sulphamylphenyl)-1,2,3-benzotriazoles and their 1-Oxides

2-(p-Sulphamylphenyl)-1,2,3-benzotriazoles and their 1-oxides have been obtained by condensation of halogen-nitrobenzenes and p-snlphamylphenylhydrazine and characteriaed. The hydrazo compound is find formed which cyclises to a benaotriazole 1-oxide in acetic acid medium and to benzotriazole in etha­nolic medium. The former can be reduced to the latter by treatment with ethanol.