Synthesis
General procedure for the synthesis of 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone from 1-cyclopropyl-2-(2-fluorophenyl)ethanone: 1-cyclopropyl-2-(2-fluorophenyl)ethanone (17.8 g, 100 mmol), iodine monobromide (62 g, 300 mmol), and 1-butyl-3-methylimidazolium bromide (8.7 g, 40 mmol) were dissolved in 150 mL of anhydrous tetrahydrofuran. The reaction was stirred at 40 °C for 4 hours. After completion of the reaction, the mixture was cooled to room temperature and the reaction was quenched by the addition of ice water. The reaction mixture was extracted with ethyl acetate and the organic phase was washed with saturated sodium bisulfite solution. The organic phase was concentrated and purified by recrystallization from ethanol to give 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone (24.5 g, 95.3% yield, 99.73% purity).
References
[1] Patent: CN105884793, 2016, A. Location in patent: Paragraph 0033; 0034; 0035
[2] Patent: WO2013/14295, 2013, A1. Location in patent: Page/Page column 19-20
[3] Patent: WO2009/122440, 2009, A1. Location in patent: Page/Page column 31
[4] Patent: CN105884599, 2016, A. Location in patent: Paragraph 0025; 0062-0064
[5] Patent: CN104418718, 2018, B. Location in patent: Paragraph 0040; 0044; 0047; 0048; 0052; 0056