2,4,6-Trichloroquinazoline

1640-60-4

20028-68-6

Part C: Preparation of 2,4,6-trichloroquinazoline. 6-Chloro-2,4-quinazoline dione (3.27 g, 1.0 equiv) was suspended in 30 mL of phosphoryl chloride and 1.5 mL of N,N-dimethylaniline was added as a catalyst. The reaction mixture was heated to reflux and held for 4.5 hours. Upon completion of the reaction, the mixture was cooled to room temperature and then slowly poured into a pre-cooled (0°C) mixture of solvents (300 mL of diethyl ether with 300 mL of water). The organic layer was separated, washed with saturated sodium chloride solution and dried over anhydrous magnesium sulfate. After filtration, the solvent was removed by concentration under reduced pressure to give 3.54 g of brown to yellow solid product in 91% yield. The structure of the product was confirmed by 1H NMR (DMSO-d6, 300 MHz): δ 8.325 (m, 1H), 8.20 (m, 1H), 8.085 (m, 1H).