3,5,6-Trichloro-1,2,4-triazine

3,5,6-Trichloro-[1,2,4]triazine (cas# 873-41-6) is a compound useful in organic synthesis.

To 18 g (93.75 mmol) of 5-bromo-6-azauracil in 150 ml of phosphorus oxychloride were added 39.2g (188 mmol) of phosphorus pentachloride and 38 ml ( 240 mmoles) of Nv/V-diethylaniline. The mixture was stirred at 120°C for 5 hours after which period the excess of solvent was evaporated. The residue was several times extracted with carbon tetrachloride. After evaporation of the solvent, the remaining oily residue was put in the refrigerator where it solidified. Yield: 13g (78%) of 3,5,6-Trichloro-1,2,4-triazine.