Boron tribromide → 1-(2-Hydroxy-5-(trifluoromethyl)phenyl)ethan-1-one

To a stirred solution of 1-[2-methoxy-5-(trifluoromethyl)phenyl]ethanone (35 g, 0.16 mol) in dry dichloromethane (400 mL) at 0° C. was added solid tetrabutylammonium iodide (2.96 g, 0.008 mol) followed by boron tribromide (33.96 mL, 0.35 mol) drop-wise. After addition, the reaction mixture was stirred at ambient temperature for 1.5 hours. The reaction mixture was cooled to 0° C. and quenched with ice. The mixture was extracted with diethyl ether (1 L). The organic layer was washed with water (2 L) and then saturated aqueous sodium chloride (1 L). After concentration of the organic layer at ambient temperature in vacuo, the crude product was purified by silica gel column chromatography (2% diethyl ether in hexane elution) to afford the title compound as a colourless oil (11.5 g, 35%).

1. additionAfter addition
2. temperatureThe reaction mixture was cooled to 0° C.
3. customquenched with ice
4. extractionThe mixture was extracted with diethyl ether (1 L)
5. washThe organic layer was washed with water (2 L)
6. customAfter concentration of the organic layer at ambient temperature in vacuo, the crude product was purified by silica gel column chromatography (2% diethyl ether in hexane elution)

ORD record

ord-65204451afbc4e25a8d953279249e02b

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09145407B2