U371920.pdf (10.77 MB)
Download file

Oxidation and rearrangement in nitrogen heterocyclic chemistry.

Download (10.77 MB)
posted on 19.11.2015, 08:47 by Alan A. Sale
This thesis reports a study of the preparation and oxidation of a range of heterocyclic N-amino compounds. A review of N-aminating agents is given in the Introduction. 1,2,4-Triazin-3(2K)-ones gave imidazolin-2-ones when treated with hydroxylamine-o-sulfonic acid or 0-(2,4-dinitrophenyl)hydroxyl- amine , probably via N-amino intermediates. However, chloramine gave 1, 2, 3-triazoles by acting as an oxidising rather than an aminating agent. These reactions were extended to cinnolin-3(2H) - one where the 2-amino derivative could be isolated. Pyrolysis and oxidation of 2-aminocinnolin-3(2K)-one both lead to new rearrangements. l-Aminoquinoxalin-2(IH)-one, prepared by amination of quinoxalin- 2(lK)-one, gave benzo-l,2,4-triazine when oxidised by lead tetraacetate, as well as products derived by interception of the N-nitrene intermediates. Four 3-substituted 1-aminooxindoles were prepared by direct amination and by reduction of cinnolin-3(2H)-ones and their different oxidative decompositions determined. The oxidation of N-amino-acetanilide was investigated for comparison. I-Amino-3-substituted benzimidazolin-2(lH)-ones were similarly studied; the corresponding tetrazenes and deaminated compounds were formed on oxidation and the N-nitrene intermediates could be intercepted with olefins or dimethyl sulfoxide. The unsubstituted l-aminobenzimidazolin-2(lH)-one gave 1-acetylbenzotriazole, however, probably via benzo-l, 2, 4-triazin-3(2H)-one. The decomposition of benzotriazole-l-carboxamide was briefly investigated. This work illustrates the diverse reactions of amino-nitrenes; generated by dehydrogenation of 1,1-disubstituted hydrazines, which include deamination, dimerisation, intramolecular rearrangement and the formation of aziridines with olefins.


Date of award


Author affiliation


Awarding institution

University of Leicester

Qualification level


Qualification name




Usage metrics