10401-18-0

To a mixed solution of N,N-dimethylformamide (60 mL) of 2-bromo-3-hydroxybenzaldehyde (1.30 g, 6.50 mmol) and potassium carbonate (2.70 g, 19.5 mmol) was added iodomethane (0.80 g, 12.9 mmol). The reaction mixture was stirred at room temperature for 16 h. After completion of the reaction, it was diluted with ethyl acetate (60 mL). The mixture was washed with saturated aqueous ammonium chloride solution (2 x 50 mL), the organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure and the residue was purified by column chromatography using a 0 to 30% ethyl acetate/hexane gradient elution to afford 2-bromo-3-methoxybenzaldehyde as a yellow oil (1.50 g, quantitative yield). Mass spectrum (electrospray positive ion mode) m/z 215.1 ([M+H]+).

[1] Patent: US2018/162868, 2018, A1. Location in patent: Paragraph 1413-1414
[2] Journal of the American Chemical Society, 2017, vol. 139, # 9, p. 3360 - 3363
[3] Patent: US2016/75711, 2016, A1. Location in patent: Paragraph 0586-0587
[4] Journal of Organic Chemistry, 2018, vol. 83, # 10, p. 5791 - 5800