Dimethylformamide → 5-Chloro-4-(trifluoromethyl)-2-pyridinecarbonitrile

To 14 ml of N,N-dimethylformamide were added 1 g of 2,5-dichloro-4-trifluoromethylpyridine, 1.71 g of zinc cyanide and 0.34 g of tetrakistriphenylphosphine palladium, and the mixture was stirred at 90° C. for 10 hours. After allowing to cool, the reaction solution was poured into water, and the resultant solution was extracted with diethyl ether three times, washed with an aqueous saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography to obtain 0.7 g of 5-chloro-4-trifluoromethylpyridine-2-carbonitrile.