2632-14-6

Preparation of 2-bromo-1-(4-ethylphenyl)ethanone (Chem. Plextr. Reg. No. 2632-14-6): 4'-Ethylacetophenone (9 mL, 60 mmol) was dissolved in 100 mL of anhydrous tetrahydrofuran, and cooled to 0 °C. Subsequently, phenyltrimethylammonium tribromide (22.6 g, 60 mmol) was added in batches and slow formation of precipitate was observed. The reaction mixture was stirred continuously at 0 °C for 1 h, after which stirring was continued at room temperature for 20 min. The concentrated reaction mixture was diluted with 200 mL of ether, washed sequentially with water (3 x 150 mL) and brine, then dried with magnesium sulfate and filtered. The filtrate was concentrated to afford the target product 2-bromo-1-(4-ethylphenyl)ethanone (15.9 g, quantitative yield). Mass spectrometry analysis showed m/z: 227, 229.03 (Br isotope mode); HPLC analysis with a retention time of 18.6 min (purity >99%).

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