The reaction was carried out with 2-chloro-6-(methylsulfonyl)pyridine (13.0 g, 67.8 mmol) and sodium cyanide (6.69 g, 136 mmol) in DMF (150 ml) with stirring at 170°C for 18 hours. After completion of the reaction, the mixture was cooled to room temperature, poured into water and extracted with ethyl acetate. The organic phases were combined, washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure and the resulting crude product was purified by silica gel column chromatography with the eluent petroleum ether-ethyl acetate (2:1, v/v) to afford 2-chloro-6-cyanopyridine (6.67 g, 71% yield) as white crystals with a melting point of 82.9-83.1 °C. IR (KBr, cm-1): 2253 (CN), 1572, 1431, 1161. 1143, 912, 854, 744. 1H-NMR (CDCl3, δ): 7.57 (1H, d, J = 8.0 Hz), 7.65 (1H, d, J = 8.1 Hz), 7.82 (1H, t, J = 7.8 Hz).
