General procedure for the synthesis of 4-methylpyridine-2-carboxylic acid from 2-cyano-4-methylpyridine: 2-cyano-4-methylpyridine (0.15 g, 1.27 mmol) was dissolved in about 10 mL of 6 M hydrochloric acid and heated and refluxed for 24 hours. During the reaction, the solution gradually changed from the initial pale yellow color to clear. Upon completion of the reaction, the solution was evaporated to dryness to give a white solid product. Purification by recrystallization from a minimal amount of distilled water resulted in 148 mg (85% yield) of 4-methylpyridine-2-carboxylic acid. The product was characterized by 1H NMR (DMSO-d6): δ = 8.65 (1H, s), 8.06 (1H, s), 7.66 (1H, s), 2.05 (3H, s).
