Reaction #1885002

Reaction equation

4-bromo-3-fluorophenol

3,4,5-trifluorophenyl-boric acid

sodium carbonate

dimethoxyethane water

→

3-fluoro-4-(3,4,5-trifluorophenyl)phenol

Yield 81.5%

Solvents

toluene

Conditions

Workup

1. 1
   TemperatureNext, the reaction solution was cooled to room temperature
2. 2
   Washwashed with 1N hydrochloric acid and water
3. 3
   DryingAfterwards, the solution was dried over magnesium sulfate
4. 4
   workup.DISTILLATIONdistilled under reduced pressure
5. 5
   Otherto remove the solvent
6. 6
   OtherSubsequently, the product was purified by silica-gel column chromatography with a mixed solvent of heptane/ethyl acetate=4/1 as the eluent
7. 7
   Otherdried under reduced pressure
8. 8
   OtherThe obtained residue was recrystallized in heptane

Procedure

At first, 75.0 g of 4-bromo-3-fluorophenol (S3-1), 82.9 g 3,4,5-trifluorophenyl-boric acid (S3-2), 13.6 g of tetrakis(triphenylphosphine)palladium, 108.5 g of sodium carbonate and 1100 ml of a mixed solvent of dimethoxyethane/water=2/1 (volume ratio) were added into a reactor under nitrogen atmosphere, and the mixture was heated to 80° C. and stirred for 4 hr. Next, the reaction solution was cooled to room temperature, added with toluene and then washed with 1N hydrochloric acid and water. Afterwards, the solution was dried over magnesium sulfate and distilled under reduced pressure to remove the solvent. Subsequently, the product was purified by silica-gel column chromatography with a mixed solvent of heptane/ethyl acetate=4/1 as the eluent and then dried under reduced pressure. The obtained residue was recrystallized in heptane to obtain 77.5 g of 3-fluoro-4-(3,4,5-trifluorophenyl)phenol (S3-3). The yield of (S3-3) from (S3-1) was 81.5%.

Source