1,2,4-Triazine N-oxides and their annelated derivatives

This review deals with the synthesis and properties of 1,2,4-triazine N-oxides and their annelated derivatives. Methods for the incorporation of the N-oxide group in the 1,2,4-triazine ring by direct oxidation and cyclisation involving nitro, nitroso, and isonitroso groups are discussed. Reactions of 1,2,4-triazine N-oxides with electrophiles, nucleophiles, and dienophiles are considered. The effect of the N-oxide group on the chemical shifts in the ¹H, ¹³C, and ¹⁴N NMR spectra and the specific features of decomposition of 1,2,4-triazine N-oxides under electron impact are analysed. The bibliography includes 107 references.