Reaktion #336889

Reaktionsgleichung

DMF

n-BuLi

5-bromo-2,2-difluorobenzo[d][1,3]dioxole

→

title compound

2,2-Difluorobenzo[d][1,3]dioxole-5-carbaldehyde

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe mixture is stirred for 30 min in the cold, then the cold bath
2. 2
   Sonstigeis removed
3. 3
   workup.STIRRINGthe reaction is stirred for 1.5 h at ambient temperature
4. 4
   Sonstigequenched with 150 mL of saturated ammonium chloride solution
5. 5
   SonstigeThe organic layer is separated
6. 6
   Waschenthe aqueous layer is washed 2× with ether
7. 7
   WaschenThe combined organics are washed with brine
8. 8
   Trocknendried over MgSO4
9. 9
   Einengenconcentrated in vacuo

Vorschrift

A solution of 127 mmol of 5-bromo-2,2-difluorobenzo[d][1,3]dioxole in 200 mL of THF is cooled under argon in a CO2/acetone bath and treated with 1.05 equivalents of n-BuLi in THF. The mixture is stirred for about 10 min in the cold, then treated with 1.2 equivalents of DMF. The mixture is stirred for 30 min in the cold, then the cold bath is removed and the reaction is stirred for 1.5 h at ambient temperature and then quenched with 150 mL of saturated ammonium chloride solution. The organic layer is separated and the aqueous layer is washed 2× with ether. The combined organics are washed with brine, dried over MgSO4 and concentrated in vacuo. Silica gel chromatography (EtOAc/hexanes eluant) yields the title compound.

Quelle