Reaction #1747839

Reaction equation

triisopropyl borate

hexane

n-butyllithium

hydrochloric acid

2-(4-bromophenyl) naphthalene

→

4-(2-naphthyl)phenylboronic acid

Yield 84.0%

Solvents

toluene

THF

Conditions

Workup

1. 1
   workup.STIRRINGThen, the reaction mixture was stirred for one hour at −60 degrees C
2. 2
   TemperatureSubsequently, the reaction mixture was warmed up to room temperature
3. 3
   workup.STIRRINGstirred for 18 hours
4. 4
   workup.STIRRINGto be stirred for one hour at room temperature
5. 5
   OtherAfter the reaction
6. 6
   DryingAfter organic phase thereof was dried with magnesium sulfate
7. 7
   workup.DISTILLATIONthe solvent was distilled away under reduced pressure
8. 8
   OtherBy crystallizing the obtained solid by toluene

Procedure

Under an argon gas atmosphere, a mixture of 50.0 g (177 mmol) of 2-(4-bromophenyl) naphthalene and 500 mL of dehydrated THF was cooled down to −60 degrees C., and added with 136 mL (212 mmol) of hexane solution of 1.56M n-butyllithium in drops while being stirred. Then, the reaction mixture was stirred for one hour at −60 degrees C. 99.6 g (529 mmol) of triisopropyl borate was dropped into the reaction solution at −60 degrees C. Subsequently, the reaction mixture was warmed up to room temperature, and stirred for 18 hours. The reaction mixture was further added with solution of hydrochloric acid to be stirred for one hour at room temperature. After the reaction, the reaction mixture was further added with toluene, so that aqueous phase thereof was eliminated. After organic phase thereof was dried with magnesium sulfate, the solvent was distilled away under reduced pressure. By crystallizing the obtained solid by toluene, 33.6 g of 4-(2-naphthyl)phenylboronic acid was obtained at an yield of 84%.

Source