Synthesis
General procedure for the synthesis of 2-methyl-4-iodopyridine from 4-chloro-2-methylpyridine: 4-chloro-2-methylpyridine (10 g, 78 mmol), sodium iodide (17.8 g, 118 mmol), and hydriodic acid (57%, 26 mL, 196 mmol) were heated and reacted in a sealed tube for 7 days at 140 °C. Upon completion of the reaction, the reaction mixture was slowly poured into ice water and neutralized with sodium hydroxide solution. Subsequently, the mixture was extracted three times with dichloromethane (300 mL each time). The organic phases were combined, dried with magnesium sulfate, filtered and concentrated under reduced pressure. The resulting product was an off-white solid (14.7 g, 85% yield) and could be used in subsequent reactions without further purification.
References
[1] Patent: WO2004/80998, 2004, A1. Location in patent: Page 27
[2] Patent: US2002/40040, 2002, A1
[3] Chemical & Pharmaceutical Bulletin, 1982, vol. 30, # 5, p. 1731 - 1737
