4349-07-9

63558-65-6

The general procedure for the synthesis of 4-chloro-5-iodopyrimidine from 4-hydroxy-5-iodopyrimidine was as follows: 12.7 mL (144.6 mmol) of oxalyl chloride was added slowly and dropwise to a stirred solution containing 7.7 mL (99 mmol) of N,N-dimethylformamide (DMF) and 150 mL of ethylene dichloride at 0°C to control the escape of drastic gas. After the gas release stopped, 10.0 g of 4-hydroxy-5-iodopyrimidine was added and the reaction mixture was heated to reflux for 3 hours. After completion of the reaction, it was cooled to room temperature and the reaction solution was partitioned between water and dichloromethane. The organic layer was separated, dried over anhydrous magnesium sulfate (MgSO?) and concentrated under reduced pressure to remove the solvent to give 9.6 g (88% yield) of the target product 4-chloro-5-iodopyrimidine. The product was confirmed by 1H-NMR (300 MHz, CDCl?): δ 8.89 (s, 1H) and 8.98 (s, 1H); electrospray ionization mass spectrometry (ESIMS) showed [M + H]+ m/z 241.1.