Reaktion #69666

Reaktionsgleichung

water

2,4-bis-benzyloxy-5-bromo-benzoic acid benzyl ester

caesium carbonate

THF

→

title compound

2,4-bis-benzyloxy-5-isopropenyl-benzoic acid benzyl ester

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated
2. 2
   Temperaturat reflux for 72 h
3. 3
   Temperaturto cool
4. 4
   Sonstigeto remove THF
5. 5
   Sonstigepartitioned between water (500 mL) and EtOAc (300 mL)
6. 6
   WaschenThe organic portion was washed with brine
7. 7
   Trocknendried (MgSO4)
8. 8
   Filtrationfiltered

Vorschrift

To a mixture of 2,4-bis-benzyloxy-5-bromo-benzoic acid benzyl ester (42.9 g, 85.7 mmol), potassium isopropenyl trifluoroborate (14.0 g, 95.2 mmol) and caesium carbonate (83.8 g, 257.1 mmol) in THF (800 mL) was added Pd(PPh3)4 (2.0 g) followed by water (150 mL). The mixture was heated at reflux for 72 h then allowed to cool to ambient. The mixture was reduced in vacuo to remove THF and then partitioned between water (500 mL) and EtOAc (300 mL). The organic portion was washed with brine, dried (MgSO4), filtered and reduced in vacuo to give the title compound (40.9 g) as a brown oil.

Quelle