2,4,5-Trichloropyrimidine

1820-81-1

5750-76-5

General procedure for the synthesis of 2,4,5-trichloropyrimidine from 5-chlorouracil: 5-chlorouracil (4.5 g, 30.82 mmol) was dissolved in phosphorochloridic acid (100 mL), followed by phosphorus pentachloride (19.2 g, 92.46 mmol). The reaction mixture was heated to reflux overnight; after completion of the reaction, it was cooled to room temperature and the solvent was removed by evaporation under reduced pressure. The residue was cooled to 0 °C and crushed ice was added slowly. The mixture was stirred for 10 min and partitioned between water and dichloromethane (DCM). The organic phase was separated and washed three times with water. The aqueous layer was combined and extracted twice with DCM. The combined organic extracts were dried over anhydrous sodium sulfate (Na2SO4), filtered and the solvent was evaporated under reduced pressure to give 2,4,5-trichloropyrimidine as a yellow oil, which did not require further purification.