Synthesis
General procedure for the synthesis of methyl 6-bromo-3-methoxypyridine carboxylate from methyl 6-bromo-3-hydroxypyridine-2-carboxylate and iodomethane: Methyl 6-bromo-3-hydroxypyridine-2-carboxylate (4 g, 17.2 mmol), iodomethane (7.15 g, 34.5 mmol) and potassium carbonate (4.76 g, 34.5 mmol) were dissolved in N,N- dimethylformamide (50 mL) and the reaction was stirred at room temperature for 3 hours. After completion of the reaction, the reaction mixture was concentrated under reduced pressure, diluted with water and extracted with ethyl acetate (50 mL x 3). The organic layers were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product methyl 6-bromo-3-methoxypyridinecarboxylate (4 g, yield: 90%). The product was identified by NMR hydrogen spectroscopy (CDCl3, 400 MHz): δ 7.56 (d, J = 8.0 Hz, 1H), 7.25 (d, J = 8.0 Hz, 1H), 3.94 (s, 3H), 3.90 (s, 3H). Mass spectrum (M + H)+: 256/258.
References
[1] Patent: WO2014/121418, 2014, A1. Location in patent: Page/Page column 45
[2] Patent: EP3255042, 2017, A2. Location in patent: Paragraph 0180; 0183
[3] Patent: WO2007/89031, 2007, A1. Location in patent: Page/Page column 84-85
[4] Patent: WO2014/209727, 2014, A1. Location in patent: Page/Page column 39
[5] Patent: WO2014/205593, 2014, A1. Location in patent: Page/Page column 41; 42
