Reaktion #58196

Reaktionsgleichung

2-bromo-5-methoxybenzoic acid

benzoyl chloride

n-butyllithium

hexane

→

2-benzoyl-5-methoxybenzoic acid

Lösungsmittel

water

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe reaction mixture is stirred for 1 hour 30 minutes at −78° C.
2. 2
   workup.WAITfor 18 hours at room temperature
3. 3
   Waschenwashed with ethyl acetate
4. 4
   workup.ADDITIONThe aqueous phase is acidified by addition of 5 N hydrochloric acid
5. 5
   Extraktionextracted with ethyl acetate
6. 6
   SonstigeThe organic phase obtained
7. 7
   Waschenis washed with brine
8. 8
   Trocknendried over anhydrous sodium sulfate
9. 9
   FiltrationAfter filtration and evaporation under reduced pressure, 5.4 g of a colourless oil
10. 10
    Sonstigeare obtained
11. 11
    Sonstigeare used without purification

Vorschrift

A solution of 2-bromo-5-methoxybenzoic acid (5 g, 21.6 mmol) in 50 mL of THF is stirred under argon at −78° C., and a 1.6 M solution of n-butyllithium in hexane (29 mL, 45 mmol) is then added dropwise. The reaction mixture is stirred for 1 hour at −78° C. and benzoyl chloride (3.2 g, 22.7 mmol) is then added dropwise. The reaction mixture is stirred for 1 hour 30 minutes at −78° C. and then for 18 hours at room temperature. The mixture is hydrolysed with 100 mL water and then washed with ethyl acetate. The aqueous phase is acidified by addition of 5 N hydrochloric acid and then extracted with ethyl acetate. The organic phase obtained is washed with brine and then dried over anhydrous sodium sulfate. After filtration and evaporation under reduced pressure, 5.4 g of a colourless oil are obtained, and are used without purification.

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