The chemistry of polyazaheterocyclic compounds. Part III. The acid-catalysed conversion of [1,2,3]triazolo[5,1-c][1,2,4]benzotriazine derivatives into 1,2,4-benzotriazines and their 1-N-oxides

Abstract

3-Phenyl[1,2,3]triazolo[5,1-c][1,2,4]benzotriazine 5-N-oxide and its 7-methyl derivative are converted, in acetic acid alone or acetic acid containing acetyl chloride, acetyl bromide, or chromium trioxide, into 1,2,4-benzotriazine 1-N-oxides. In contrast, warming the triazolobenzotriazine N-oxides with aqueous sulphuric acid in acetic acid yields the deoxy-compounds, 3-benzoyl-1,2,4-benzotriazine and its 7-methyl derivative. 3-Phenyl[1,2,3]triazolo[5,1-c][1,2,4]benzotriazine and its 7-methyl derivative similarly but less readily undergo acid-catalysed conversion into 1,2,4-benzotriazines. The course of these reactions is discussed.