Reaction #43920

Reaction equation

sodium thiosulfate

4-bromo-3,5-dimethylphenol

N-fluoropyridinium triflate

→

title compound

Yield 36.2%

4-bromo-2-fluoro-3,5-dimethylphenol

Yield 36.2%

Solvents

1,2-dichloroethane

Conditions

Workup

1. 1
   Temperaturethe mixture was heated
2. 2
   Temperatureunder reflux for 7 hr
3. 3
   Extractionextracted with ethyl acetate
4. 4
   WashThe extract was washed successively with water and saturated brine
5. 5
   Dryingdried over anhydrous magnesium sulfate
6. 6
   Concentrationconcentrated under reduced pressure
7. 7
   OtherThe residue was purified by silica gel column chromatography (ethyl acetate:hexane=0:100-30:70)

Procedure

To a solution of 4-bromo-3,5-dimethylphenol (2.00 g, 9.95 mmol) in 1,2-dichloroethane (20 mL) was added N-fluoropyridinium triflate (6.15 g, 24.9 mmol), and the mixture was heated under reflux for 7 hr. The reaction mixture was treated with 1 M aqueous sodium thiosulfate solution, and extracted with ethyl acetate. The extract was washed successively with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=0:100-30:70) to give the title compound (0.790 g, yield 36%) as a colorless oil.

Source