1513-65-1

685517-67-3

General procedure for the synthesis of 2,6-difluoro-3-iodopyridine from 2,6-difluoropyridine: 2,6-difluoropyridine (1.15 g, 10 mmol) was dissolved in toluene (300 ml) at -78 °C and under nitrogen protection, and n-butyllithium (n-BuLi, 4.8 ml, 12 mmol, 1.2 eq.) was slowly added. The reaction mixture was stirred continuously at -78 °C for 4 hours. Subsequently, iodine (2.53 g, 10 mmol) was added while the temperature was kept below -70 °C. The reaction mixture was gradually warmed up to room temperature and the reaction was quenched with 10 ml of water. The organic solvent was removed by distillation under reduced pressure and the residue was collected by filtration. Purification by silica gel column chromatography (eluent ratio: petroleum ether/ethyl acetate = 50:1 to 5:1) afforded the target product 2,6-difluoro-3-iodopyridine as a solid (1.49 g, 6.1 mmol, 61% yield). The product was analyzed by ESI-MS (M+1): 242, which is consistent with the theoretically calculated value C5H2F2I (241).