13472-85-0

13472-61-2

The general procedure for the synthesis of 5-bromo-2-methoxypyridine from 5-bromo-2-methoxypyridine was as follows: n-butyllithium (1.5 M in hexane solution, 4.98 mL, 7.47 mmol) was slowly added to a solution of isopropylmagnesium chloride (1.61 M in THF, 4.64 mL, 7.47 mmol) in THF (20 mL) under ice bath cooling conditions. The reaction mixture was stirred for 5 min to form a yellow solution after which 5-bromo-2-methoxypyridine (1.405 g, 0.98 mL, 7.10 mmol, 95%) was added. The resulting solution was continued to be stirred at 0 °C for 45 min. Molecular iodine (3.79 g, 14.94 mmol) was then added and the reaction mixture was stirred at 0°C for 30 minutes and then at room temperature for 1 hour. Upon completion of the reaction, the reaction was quenched by the addition of aqueous ammonium chloride (5 mL) and the organic and aqueous phases were separated. The aqueous phase was extracted with ethyl acetate (2 x 75 mL), and the combined organic layers were dried with magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (ethyl acetate-heptane, 5-80%) to afford the target product 5-iodo-2-methoxypyridine.