Aza 2 azoniaallene cations 3(denoted also as azo carbenium ions) were generated in situ as reactive intermediates by chlorination of pinakolone hydrazones 1 with tert butyl hypochlorite and treatment of the resulted(1 choroalkyl)azo compounds 2 with a Lewis acid (SbCl 5). The allene like cations 3 were trapped by cycloaddition to the triple bond of nitriles giving 3 H 1,2,4 triazolium salts 4. The initially formed heterocycles 4 couldn′t be isolated but underwent smooth 1,2 tert butyl shift accompanied by elimination of isobutene to afford 1 H 1,2,4 triazolium salts 5, from which 1,3,5 trisubstituted 1 H 1,2,4 triazoles 6 have been obtained in moderate to high yields after basic work up. Heterocycles 6 are characterized by elemental analysis and IR, 1H NMR measurements.
