The general procedure for the synthesis of 2-bromo-4-methoxypyridine from sodium methanol and 2-bromo-4-chloropyridine was as follows: sodium methanol (0.35 g, 6.48 mmol) was added to a solution of 2-bromo-4-chloropyridine (1.0 g, 5.2 mmol) in dimethyl sulfoxide (DMSO, 10 mL). After the addition was completed, the reaction mixture was stirred at 120 °C for 24 hours. After completion of the reaction, the mixture was cooled to room temperature and extracted with ethyl acetate (EtOAc). The organic layers were combined and dried over anhydrous sodium sulfate (Na2SO4) and subsequently concentrated under reduced pressure. Purification of the residue by preparative high performance liquid chromatography (HPLC) gave 2-bromo-4-methoxypyridine (0.25 g, 25% yield) as a colorless oil. The mass spectrometry (MS) electrospray ionization (ESI) calculated value was 189 for C6H6BrNO [M + H]+ and the measured value was 189.
