Heterocyclic N-oxides. Part VI. Synthesis and nuclear magnetic resonance spectra of 3-aminobenzo-1,2,4-triazines and their mono- and di-N-oxides
Abstract
A series of 3-aminobenzo-1,2,4-triazine derivatives has been synthesised and their oxidation with hydrogen peroxide in acetic acid studied. The position of the N-oxide group(s) in the products has been established by analysis of n.m.r. spectra. It is shown that oxidation of 3-aminobenzo-1,2,4-triazines at room temperature leads almost exclusively to the 2-oxide whereas prolonged oxidation at 50° yields the 1,4-di-N-oxide.