6299-92-9Relevant articles and documents
Electrochemical reduction of o-nitrophenylhydrazides into 1,2,4-benzotriazines.
Chibani, A.,Hazard, R.,Tallec, A.
, p. 343 - 352 (2007/10/02)
Phenylhydroxylamines, obtained in aqueous medium, by electroreduction of o-nitrophenylhydrazides (o-NO2-C6H4-NH-NHCOR), undergo a disproportionation reaction leading finally to the corresponding o-amino compound; the latter partially rearranges into an o-amidophenylhydrazine (o-RCONH-C6H4-NH-NH2).In a basic media, the disproportionation reaction is concurrent with a ring closure of the intermediate hydroxylamine giving rise to a 1,2,4-benzotriazine.The latter is also obtained by anodic oxidation of the amine, mixed with anilide resulting from the hydrazine oxidation.Electroreduction, immediately followed by an anodic oxidation gives rise to about 50percent yield in the expected triazine.In an acidic media, disproportionation is faster, but the resulting amine undergoes a ring closure reaction into dihydrobenzotriazine when R = H or CH3.Subsequent oxidation of the latter gives rise to 75percent yield of the triazine, mixed with N-aminobenzimidazole resulting from the hydrazine.When R = Ph, the amine is stable but only very poor yields of triazine are obtained by anodic oxidation; the major evolution is probably the formation of an unstable benzoylbenzotriazole.Key words: cyclic voltammetry, controlled potential reduction and oxidation, 1,2,4-benzotriazine, 1-amino-2-alkylbenzimidazoles, organic electrosynthesis.
