A Multicomponent Electrosynthesis of 1,5-Disubstituted and 1-Aryl 1,2,4-Triazoles.

A novel electrochemical route has been developed for the synthesis of 1,5-disubstituted and 1-aryl 1,2,4-triazoles from aryl hydrazines, paraformaldehyde, NH4OAc, and alcohols. In this multicomponent reaction system, alcohols act as solvents as well as reactants and NH4OAc is used as the nitrogen source. With the assistance of reactive iodide radical or I2 and NH3 electrogenerated in situ, this process could effectively avoid the use of strong oxidants and transition-metal catalysts and be smoothly carried out at room temperature to give a wide array of 1,2,4-triazole derivatives in good to high yields. Preliminary studies reveal that the reaction mechanism involves a radical process.