Reaktion #585171

Reaktionsgleichung

butyllithium

hexane

2,2,6,6-tetramethylpiperidine

4-bromo-1,2-difluorobenzene

dry ice

→

title compound

Ausbeute 57.0%

6-Bromo-2,3-difluorobenzoic acid

Ausbeute 57.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONThe solution was carefully poured
2. 2
   Temperaturto warm to room temperature
3. 3
   EinengenThe solution was concentrated under reduced pressure
4. 4
   workup.ADDITIONthe residue was poured into water
5. 5
   WaschenAfter the solution was washed with diethylether
6. 6
   workup.ADDITIONthe aqueous layer was made acidic by the addition of 6N hydrochloric acid, and organic matter
7. 7
   Extraktionwas extracted with dichloromethane
8. 8
   WaschenThe extract was washed with saturated brine
9. 9
   Trocknendried over anhydrous magnesium sulfate
10. 10
    Einengenconcentrated under reduced pressure

Vorschrift

A solution of 1.6M butyllithium in hexane (60 mL, 96 mmol) was diluted with tetrahydrofuran (180 mL) under an argon atmosphere, and cooled to −78° C. To the solution, were added dropwise 2,2,6,6-tetramethylpiperidine (16.2 g, 116 mmol) and subsequently 4-bromo-1,2-difluorobenzene (15.4 g, 80 mmol), and the mixture was stirred at the same temperature for 2 hours. The solution was carefully poured onto crushed dry ice, and the mixture was allowed to warm to room temperature. The solution was concentrated under reduced pressure, and the residue was poured into water. After the solution was washed with diethylether, the aqueous layer was made acidic by the addition of 6N hydrochloric acid, and organic matter was extracted with dichloromethane. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give the title compound (10.8 g, 57% yield).

Quelle