Synthesis
2,6-Dibromo-3-hydroxypyridine (12 g, 47 mmol) was used as starting material and mixed with potassium carbonate (6.0 g, 43 mmol) and iodomethane (10.1 mL, 162 mmol) in DMSO (20 mL) to form a suspension. The reaction mixture was heated to reflux for 2 hours. Upon completion of the reaction, the mixture was poured into water (60 mL), gently heated at 50 °C and stirred for 30 min. Subsequently, the reaction mixture was cooled to room temperature and the precipitated solid was collected by filtration and dried under vacuum. Finally, the dried residue was crystallized from cyclohexane to afford the target product 2,6-dibromo-3-methoxypyridine (10.1 g, 80% yield) as a light orange solid. The product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ= 7.66 (d, J = 8.0 Hz, 1H), 7.52 (d, J = 8.0 Hz, 1H), 3.90 (s, 3H); mass spectrometry analysis showed ES + ve m/z 266,268,270 (M + H)+.
References
[1] Bioorganic and Medicinal Chemistry, 2014, vol. 22, # 15, p. 4298 - 4311
[2] Australian Journal of Chemistry, 1981, vol. 34, # 4, p. 927 - 932
[3] Bioorganic and Medicinal Chemistry Letters, 2014, vol. 24, # 24, p. 5630 - 5634
[4] Patent: EP3255042, 2017, A2. Location in patent: Paragraph 0088; 0089
[5] Patent: EP2017277, 2009, A1. Location in patent: Page/Page column 30
