Abstract 4, 5-Dihydro-4, 5-dimethylene-1-phenyl-1, 2, 3-triazole (4), the 1, 2, 3-triazole analogue ofo-quinodimethane, can be generated in situ from 4, 5-bis (bromomethyl) derivative (3) by sodium iodide induced 1, 4-elimination process. By trapping the 1, 4-