2142-69-0

26767-16-8

A solution of 1-(2-bromophenyl)ethan-1-one (10 g, 50.24 mmol, 1.00 eq.) in pyridine (80 mL) was added to a 250 mL three-necked round-bottomed flask under nitrogen protection. Selenium dioxide (22 g, 198.27 mmol, 3.95 equiv) was then added. The reaction mixture was placed in a 120°C oil bath and stirred for 18 hours. After completion of the reaction, it was cooled to room temperature and filtered to remove solids. The filtrate was concentrated under reduced pressure and the residue was dissolved in 100 mL of water. The aqueous phase was washed with ethyl acetate (2×50 mL), and then the pH of the aqueous phase was adjusted to 1-2 with 4 mol/L hydrochloric acid.The aqueous phase was extracted with ethyl acetate (3×80 mL), and the organic phases were combined and dried with anhydrous sodium sulfate. The desiccant was removed by filtration and the filtrate was concentrated under reduced pressure to give 2-(2-bromophenyl)-2-oxoacetic acid (10 g, 87% yield) as a yellow oil. Mass spectrum (ESI) m/z 230 ([M + H]+).