Synthesis
(C) 500 mL of methanol was added to 59.4 g (253 mmol) of crude 2-fluoro-4-iodopyridine obtained from step (B) and stirred until completely dissolved. Subsequently 21.5 g (398 mmol) of sodium methanol was added and the reaction was heated to reflux for 3 hours. Upon completion of the reaction, 300 mL of water was added to quench the reaction, followed by removal of methanol by distillation under reduced pressure. The reaction mixture was extracted with ether and the organic layers were combined and dried over anhydrous sodium sulfate. After filtration, the solvent was removed by reduced pressure distillation to afford the crude product 4-iodo-2-methoxypyridine 56.7 g (crude yield: 91%). The structure of the product was confirmed by 1H-NMR (CDCl3, 400 MHz): δ (ppm) = 3.86 (s, 3H), 7.12-7.16 (m, 2H), 7.79 (d, 1H, J = 5.6 Hz).
