Synthesis
Purified 4-methoxy-3-hydroxyacetophenone (24.9 g; 0.15 mol) was dissolved in dimethylformamide (80 ml) at room temperature. Potassium carbonate (27.6 g; 0.20 mol) was added to the reaction system, followed by the slow dropwise addition of ethyl bromide (18.0 g; 0.165 mol) at a temperature not exceeding 35 °C with simultaneous stirring and cooling to control the reaction temperature. The reaction mixture was stirred continuously at 30-35 °C for 5 h. Upon completion of the reaction, the system was cooled to below 10 °C, diluted with deionized water (240 ml) and stirring was continued at 0-10 °C for 2 h to promote product precipitation. The solid product was collected by filtration, washed with deionized water (2 x 100 ml) to remove residual inorganic salts and solvent, and finally dried under vacuum at 40 °C to constant weight to afford 1-(3-ethoxy-4-methoxyphenyl)ethanone (26.32 g; yield 90.4%; HPLC purity: 99.8%).
References
[1] Patent: WO2017/59040, 2017, A1. Location in patent: Paragraph 0078
[2] European Journal of Organic Chemistry, 2006, # 17, p. 4044 - 4054
[3] Organic Letters, 2017, vol. 19, # 11, p. 2877 - 2880
[4] Patent: CN105622380, 2016, A. Location in patent: Paragraph 0044; 0045; 0046; 0047
[5] Patent: US2007/259868, 2007, A1. Location in patent: Page/Page column 16
