Synthesis
Step 1. 2,5-dibromopyridine (5.5 g, 23.2 mmol) and sodium methanolate (3.76 g, 69.6 mmol) were dissolved in methanol (60 mL), and the mixture was placed in a sealed reaction vessel and heated to react for 42 hours at 70 °C. After completion of the reaction, the reaction mixture was cooled to room temperature, diluted with water (50 mL) and extracted with ethyl acetate (2 x 100 mL). The organic layers were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure to give the light yellow oily product 5-bromo-2-methoxypyridine (4.1 g, 95% yield). Thin layer chromatography (TLC) analytical conditions: 10% ethyl acetate/90% hexane, Rf value of 0.57.
References
[1] Patent: US2002/65296, 2002, A1
[2] Patent: US2004/102636, 2004, A1
[3] Patent: EP1042305, 2005, B1. Location in patent: Page/Page column 32-33
[4] Tetrahedron, 1985, vol. 41, # 7, p. 1373 - 1384
[5] Patent: EP1308441, 2003, A1