3-Bromo-6-fluoro-2-methylpyridine (4 g, 21 mmol) and sodium cyanide (4 g, 82 mmol) were reacted in dimethyl sulfoxide (DMSO, 100 mL). The reaction mixture was stirred at 100°C for 2 hours. After completion of the reaction, the mixture was poured into water (100 mL) and extracted with ethyl acetate (2 x 100 mL). The organic layers were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure. Purification by fast column chromatography (silica gel, 10 g, with a petroleum ether solution of 10% ethyl acetate as eluent) afforded 5-bromo-6-methyl-2-cyanopyridine (0.6 g, 15% yield) as a white solid; mass spectra (MS): m/e = 197.0 [M + H]+.
