[Synthesis]
Copper dibromide (CuBr2, 955 mg, 4.18 mmol) and ethyl acetate (EtOAc, 10 mL) were added to a two-necked round-bottomed flask fitted with a reflux condenser tube under argon protection. The suspension was stirred for 20 min. Subsequently, 4'-bromo-3'-chloroacetophenone (500 mg, 2.14 mmol), which was pre-dissolved in ethyl acetate (EtOAc, 10 mL), was added to the reaction mixture and the reaction was heated at 80 °C for 1 hour. During the reaction, copper dibromide (CuBr2, 460 mg, 2.06 mmol) was added additionally and the reaction mixture was continued to be stirred at 80 °C overnight. Upon completion of the reaction, the suspension was cooled to room temperature, filtered through a diatomaceous earth pad and washed with ethyl acetate (EtOAc). The combined filtrates were washed with saturated sodium bicarbonate (NaHCO3) solution, the organic layer was dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. Purification by silica gel fast column chromatography (petroleum ether/ethyl acetate=4:1) afforded the target product 2-bromo-1-(4-bromo-3-chlorophenyl)ethanone (582 mg, 87%) as a yellow viscous oil. Nuclear magnetic resonance hydrogen spectrum (1H NMR, 300 MHz, CDCl3) δ 8.06 (d, J = 2.1 Hz, 1H, Har), 7.77 (d, J = 8.5 Hz, 1H, Har), 7.71 (dd, J = 8.4, 2.0 Hz, 1H, Har), 4.38 (s, 2H, CH2). Nuclear magnetic resonance carbon spectrum (13C NMR, 75 MHz, CDCl3) δ 134.7 (CH), 131.0 (CH), 128.3 (CH), 30.4 (CH2). High Resolution Mass Spectrometry (HRMS, ESI) [M + H]+ C8H6Br2ClO: Calculated value 310.8468, measured value 310.8455. |