The reaction was carried out in acetone (190 mL) at reflux for 6 hours with methyl 6-chloro-5-hydroxynicotinate (1.8 g, 9.6 mmol), iodomethane (2M ether solution, 5.8 mL, 11.6 mmol) and potassium carbonate (2.0 g, 14.5 mmol). Upon completion of the reaction, the reaction mixture was concentrated using a rotary evaporator and subsequently diluted by adding water (100 mL). The resulting white precipitate was collected by filtration and washed with additional water to afford the target product methyl 6-chloro-5-methoxynicotinate as a white solid (1.33 g, 68% yield) with a melting point of 83-85 °C. The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3) δ 8.60 (d, 1H), 7.77 (d, 1H), 3.98 (s, 3H), 3.96 (s, 3H) and GC-MS (calculated value: C8H8ClNO3 [M]+ 201, measured value: 201).
