To a stirred solution of 6-methylpyridine-3-carboxylic acid (40 g; 290 mmol; 1 equiv.) in methanol (0.75 L) was slowly added concentrated sulfuric acid (40 mL), and the reaction mixture was heated to reflux and held for 17 hours. Upon completion of the reaction, the mixture was concentrated to dryness under reduced pressure. Subsequently, the pH of the residue was adjusted to 7 with ice-cold saturated aqueous NaHCO3 and solid NaHCO3. The aqueous layer was extracted with ethyl acetate (3 x 500 mL), the organic layers were combined, washed with saturated brine, dried with anhydrous sodium sulfate, and the solvent was removed by filtration and under reduced pressure to give methyl 6-methylnicotinate (33 g, 75% yield) as an off-white solid. The product was confirmed by 1H NMR (CDCl3): δ 9.06 (s, 1H), 8.13 (dd, 1H, J = 2,8Hz), 7.20 (d, 1H, J = 8Hz), 3.89 (s, 3H), 2.58 (s, 3H).LCMS analysis showed: m/z = 152.4 [M + H]+, retention time RT = 2.36 min (using program P1, column W).
