Reaction of 1,1-disubstituted hydrazines with bromine in the presence of aryl- and heteroarylnitroso compounds in acid media: A general method for the synthesis of 1-aryl(heteroaryl)-3,3-disubstituted triazene 1-oxides
摘要:
We have worked out a method for the synthesis of 1,3,3-trisubstituted triazene 1-oxides based upon reaction of 1,1-disubstituted hydrazines with bromine in the presence of aryl- and heteroarylnitroso compounds in acid media. Obtained are a broad range of triazene 1-oxides, among which hitherto unknown compounds of the series of pyrazole and 3,3-dialkyltriazene 1-oxides that contain functional groups at the alkyl part of the molecule. We propose a reaction scheme which includes in situ formation of diazenium cations and reaction of them with nitroso compounds that are present in the system. By means of PMR, C-13, and N-14 NMR spectroscopy, and mass spectroscopy, it has been shown that in all the prepared compounds the oxidated nitrogen atom is at the N1 position of the triazene N-oxide group.