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General procedure for the synthesis of methyl 3-iodopyridinecarboxylate from methanol and 3-iodopyridine-2-carboxylic acid: a mixture of 3-iodopyridine-2-carboxylic acid (D1, 3.0 g, 0.012 mol) and concentrated sulfuric acid (2 mL) in methanol (100 mL) was heated and refluxed for 18 hr at 65 °C. After completion of the reaction, the solvent was removed by rotary evaporator under reduced pressure. The residue was alkalized to neutrality with solid sodium bicarbonate and subsequently extracted with ethyl acetate (3 × 100 mL). The organic phases were combined, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give methyl 3-iodopyridinecarboxylate (2.2 g, 70% yield). NMR hydrogen spectrum (CDCl3, 250 MHz) δH: 4.01 (3H, s), 7.13 (1H, dd), 8.29 (1H, dd), 8.64 (1H, dd). Mass spectrum (electrospray ionization): calculated value of 263 and measured value of 264 (MH+) for C7H6INO2.

[1] Patent: US2008/312209, 2008, A1. Location in patent: Page/Page column 13
[2] Patent: WO2007/7018, 2007, A1. Location in patent: Page/Page column 39
[3] Patent: WO2006/25783, 2006, A1. Location in patent: Page/Page column 120-121