2,3,5,6-Tetramethylphenol → 4-Bromo-2,3,5,6-tetramethylphenol

To a suspension of 2,3,5,6-tetramethylphenol (5.10 g, 34.0 mmol) in acetic acid (90 ml) was added dropwise a solution of bromine (1.98 mL, 38.6 mmol) in acetic acid (30 mL) at room temperature, and the mixture was stirred for 5 hr. The reaction mixture was concentrated under reduced pressure, and the residue was diluted with ethyl acetate, and washed successively with aqueous sodium thiosulfate solution and saturated brine. The organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The precipitated crystals were washed with petroleum ether to give the title compound (5.10 g, yield 66%) as pale-yellow crystals. The mother solution was concentrated under reduced pressure, and washed with petroleum ether to give second crop (1.38 g, yield 18%).

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. additionthe residue was diluted with ethyl acetate
3. washwashed successively with aqueous sodium thiosulfate solution and saturated brine
4. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. washThe precipitated crystals were washed with petroleum ether

ORD record

ord-be2e05e9a57c4cdcb08fb31ac46ec4f8

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08598226B2