Sulfuric acid (15 mL) and toluene (100 mL) were added to a concentrated solution of 2-hydroxynicotinic acid (50 g) in methanol (500 mL). The reaction mixture was stirred at room temperature for 28 hours before a Dean-Stark reflux device was installed and the reaction solution was neutralized with aqueous potassium carbonate, followed by evaporation of the solvent. Saturated aqueous ammonium chloride and chloroform were added to the residue, the organic layer was separated and the aqueous layer was extracted with chloroform. The organic layers were combined, dried with anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to afford methyl 2-hydroxynicotinate (46 g, 84% yield) as a white solid.1H NMR (300 MHz, CDCl3) δ: 3.92 (s, 3H), 6.45 (dd, J=7.3,6.4 Hz, 1H), 7.78 (dd, J=6.4,2.4 Hz, 1H). 8.29 (dd, J=7.3,2.4Hz, 1H).
