Synthesis of 2‐Substituted 1,2,3‐Triazoles via an Intramolecular N–N Bond Formation

An efficient synthesis of 2‐aryl 1,2,3‐triazoles based on an intramolecular N–N bond formation is described. Selective activation of bis‐hydrazone at the dimethylamino hydrazone group with MeI forms a mono‐hydrazonium species. Treatment of the hydrazonium species with a base smoothly leads to the formation of a wide variety of 2‐aryl‐1,2,3‐triazoles in good to excellent yields. The reaction likely follows an intramolecular SN2 displacement mechanism with the trimethylammonium moiety serving as a good leaving group for the intramolecular N–N bond formation. An intramolecular N–N bond formation leads to a wide variety of 2‐aryl 1,2,3‐triazoles based on an intramolecular N–N bond formation is described. The reaction likely follows an intramolecular SN2 displacement mechanism with the trimethylammonium moiety serving as a good leaving group for the intramolecular N–N bond formation.