tert-Butyl carbamate (960 mg), cesium carbonate (5.06 g), Pd2(dba)3 (1.07 g), and Xantphos (1.35 g) were added to a toluene solution (40 ml) containing 2-chloro-5-fluoro-4-iodopyridine (2 g), followed by stirring at 100° C. for 3 hours. The reaction solution was adjusted to room temperature and water was added to the reaction solution, followed by extraction with ethyl acetate. The organic layers were washed with saturated saline and dried over anhydrous sodium sulfate. The solvent was distilled away under reduced pressure and the obtained residue was purified by silica gel chromatography (n-hexane:ethyl acetate=9:1 to 4:1). A yellow oily matter of tert-butyl (2-chloro-5-fluoropyridin-4-yl)carbamate (1.53 g) was thus obtained.
