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4-Cyano-2-fluoropyridine is an important raw material and intermediate used in organic synthesis, pharmaceuticals and agrochemicals.

General procedure for the synthesis of 4-cyano-2-fluoropyridine from 2-chloro-4-cyanopyridine: 2-chloro-4-cyanopyridine (6.0 g, 43.5 mmol), potassium fluoride (7.56 g, 130.3 mmol), and tetrabutylphosphonium bromide (14.8 g, 43.7 mmol) were dissolved in 1-methyl-2-pyrrolidinone (20 mL) and heated to 100° C. The reaction was carried out at 100° C for 18 h. The reaction was carried out in the following manner. C for 18 hours. After completion of the reaction, the reaction mixture was diluted with water and extracted with ethyl acetate (EtOAc). The organic phase was washed sequentially with water and brine, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure to afford the target product 4-cyano-2-fluoropyridine (2.3 g, 43% yield). The mass spectrum (ES) showed m/z 123.1 ([M + H]+). NMR hydrogen spectrum (400 MHz, CDCl3) δ 8.43 (d, 1H, J = 5.2 Hz), 7.45 (m, 1H), 7.22 (m, 1H).

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[5] Journal of Organic Chemistry, 2015, vol. 80, # 24, p. 12137 - 12145