Synthesis of multi-substituted 1,2,4-triazoles utilising the ambiphilic reactivity of hydrazones.

The synthesis of -alkyl-1-1,2,4-triazoles from ,-dialkylhydrazones and nitriles formal [3+2] cycloaddition including the -chlorination/nucleophilic addition/cyclisation/dealkylation sequence was developed. This sequential reaction utilising the generation of hydrazonoyl chloride based on the ambiphilic reactivity of hydrazones afforded a variety of multi-substituted -alkyl-triazoles in high yields. The synthetic utility of multi-substituted triazoles was also demonstrated by further transformations.