Reaction #2487417

Reaction equation

2-bromopyridine

dibenzo[b,d]furan-4-ylboronic acid

potassium phosphate tribasic monohydrate

toluene

→

product

Yield 62.2%

4-(2-pyridyl)dibenzo[b,d]furan

Yield 62.2%

Solvents

water

Conditions

Workup

1. 1
   OtherThe reaction mixture was degassed with N2 for 20 minutes
2. 2
   Temperaturethe reaction mixture was refluxed for 18 h
3. 3
   TemperatureAfter cooling
4. 4
   Otherthe aqueous layer was removed
5. 5
   Othertoluene was evaporated under reduced pressure
6. 6
   workup.DISSOLUTIONThe residue was dissolved in dichloromethane
7. 7
   Washeluting with dichloromethane
8. 8
   OtherThe crude product was chromatographed on silica gel with 20-25% ethyl acetate in hexane

Procedure

To a 1 L round-bottom flask was added 2-bromopyridine (13.80 mL, 142 mmol), dibenzo[b,d]furan-4-ylboronic acid (25 g, 118 mmol), dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine (1.936 g, 4.72 mmol) and potassium phosphate tribasic monohydrate (81 g, 354 mmol) with toluene (350 mL) and water (35 mL). The reaction mixture was degassed with N2 for 20 minutes. Pd2(dba)3 (2.16 g, 2.35 mmol) was added and the reaction mixture was refluxed for 18 h. Completion of the reaction was confirmed by HPLC, GC and TLC. After cooling, the aqueous layer was removed and toluene was evaporated under reduced pressure. The residue was dissolved in dichloromethane and passed through one inch silica gel plug on a frit, eluting with dichloromethane. The crude product was chromatographed on silica gel with 20-25% ethyl acetate in hexane to give 18 g (62%) of the product. The product was confirmed by HPLC (99.6% purity) and GC/MS.

Source