6-Phenyl-1,2,4-triazine 4-oxide → 6-Phenyl-1,2,4-triazine

Participants

Reaction Steps

A mixture of 6-phenyl-[1,2,4]triazine-4-oxide (27 g, 156 mmol) and triethyl phosphite (500 ml) was heated under reflux for 30 min. The cooled reaction mixture was evaporated tit vacuo and the residue was purified by flash chromatography (SiO2; 50% Et2O in hexanes) to afford 19 g (121 mmol, 78%) of 6-phenyl-[1,2,4]triazine as a yellow solid. δH (400 MHz; CDCl3) 7.56-7.59 (3H, m, aromatics), 8.10-8.14 (2H, m, aromatics), 9.03 (1H, s, triazine H5), 9.65 (1H, s, triazine H3); m/z (ES+) 158 (M++H, 100%).

Provenance & Evidence