A formal [3+2] cycloaddition reaction of N-methylimidazole as a masked hydrogen cyanide: access to 1,3-disubstitued-1H-1,2,4-triazoles.

N-Methylimidazole (NMI) can act as a masked HCN in the synthesis of 1,3-disubstitued-1H-1,2,4-triazoles via a formal cycloaddition reaction of hydrazonoyl chloride with NMI. The product was proved to be formed via an initial nucleophilic substitution of hydrazonoyl chloride with NMI following cyclization and two sequential C-N bond cleavages.