Using 5-amino-3-methylpyridine-2-carbonitrile (18.0 g, 135 mmol) as raw material, a 1.6 M aqueous solution of sodium nitrite (10.3 g, 149 mmol) was slowly added to a mixture of its water (243 mL) and concentrated sulfuric acid (67.5 mL) at 0 °C. The reaction mixture was gradually warmed to room temperature and subsequently stirred at 100 °C for 3 hours. Upon completion of the reaction, it was cooled to room temperature and extracted with ethyl acetate (3 x 75 mL). The organic layers were combined, washed sequentially with water (2 × 75 mL) and saturated aqueous sodium chloride solution (2 × 75 mL), dried, filtered and concentrated under reduced pressure to give 5-hydroxy-3-methylpyridine-2-carbonitrile (16 g, 120 mmol, 89% yield) as a yellow solid.1H NMR (400 MHz, DMSO-d6) δ 11.07 (brs, 1H) 8.08 (d, J = 2.6Hz, 1H), 7.20 (d, J = 2.3Hz, 1H), 2.40 (s, 3H).
