REACTION OF 1,1-DISUBSTITUTED HYDRAZINES WITH BROMINE IN THE PRESENCEOF ARYL-NITROSO AND HETEROARYL-NITROSO COMPOUNDS IN ACID-MEDIA - A GENERAL-METHOD FOR THE SYNTHESIS OF 1-ARYL(HETEROARYL)-3,3-DISUBSTITUTEDTRIAZENE 1-OXIDES

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-dia lkyltriazene 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 compo unds that are present in the system. By means of PMR, C-13, and N-14 N MR spectroscopy, and mass spectroscopy, it has been shown that in all the prepared compounds the oxidated nitrogen atom is at the N1 positio n of the triazene N-oxide group.