Reaktion #2146691

Reaktionsgleichung

4′-benzoyloxyacetophenone

tetra-n-butyl ammonium tribromide

→

4′-benzoyloxy-2-bromoacetophenone

Ausbeute 73.5%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISTILLATIONwas distilled off under reduced pressure
2. 2
   Sonstigeto remove the solvent
3. 3
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
4. 4
   Waschenwashed twice with water
5. 5
   Waschenwashed with an aqueous saturated sodium chloride solution
6. 6
   TrocknenAfter the ethyl acetate layer was dried over anhydrous sodium sulfate
7. 7
   Einengenconcentrated under reduced pressure
8. 8
   Sonstigethe resulting crude product was purified by silica gel column chromatography (elution solvent: hexane/methylene chloride=1/1)

Vorschrift

13.50 g (corresponding to 59.66 mmol) of 4′-benzoyloxyacetophenone was dissolved in 1100 ml of methanol, and 34.52 g (corresponding to 71.59 mmol) of tetra-n-butyl ammonium tribromide was added thereto. The mixture was stirred overnight at room temperature, and was distilled off under reduced pressure to remove the solvent. The residue was dissolved in ethyl acetate and washed twice with water and then washed with an aqueous saturated sodium chloride solution. After the ethyl acetate layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure, the resulting crude product was purified by silica gel column chromatography (elution solvent: hexane/methylene chloride=1/1), to obtain 13.38 g (corresponding to 43.84 mmol) of 4′-benzoyloxy-2-bromoacetophenone (FIG. 3, Step 4).

Quelle