Reaction #992709

Reaction equation

water

n-BuLi

6-bromo-2,3-di-p-tolyl-benzo[b]thiophene

2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

white solid

Yield 85.5%

2-(2,3-di-p-tolyl-benzo[b]thiophen-6-yl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane

Yield 85.5%

Solvents

THF

Conditions

Workup

1. 1
   Otherat −78° C
2. 2
   workup.STIRRINGstirred at room temperature for one hour
3. 3
   ExtractionThen an organic layer was extracted with brine and methylene chloride
4. 4
   DryingThe extracted organic layer was dried with anhydride magnesium sulfate
5. 5
   Filtrationfiltered
6. 6
   Otherremoved of solvent
7. 7
   OtherThe organic layer was purified through chromatography (silica, hexane)

Procedure

Under argon atmosphere, in a 500 ml round-bottomed flask, 5 g (12.75 mmol) of 6-bromo-2,3-di-p-tolyl-benzo[b]thiophene was dissolved in 150 ml of THF, and 6.12 ml (15.31 mmol) of n-BuLi 2.5M (hexane) was added thereto at −78° C. The resulting solution was stirred at −78° C. for 2 hours. Then 3.4 ml (16.58 mmol) of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was added thereto and stirred at room temperature for one hour. The reaction was ended by adding 50 ml of water. Then an organic layer was extracted with brine and methylene chloride. The extracted organic layer was dried with anhydride magnesium sulfate, filtered and removed of solvent. The organic layer was purified through chromatography (silica, hexane), and 4.8 g (yield 79%) of white solid product was obtained by increasing the polarity of the developing solvent.

Source