Reaction #2146691

Reaction equation

4′-benzoyloxyacetophenone

tetra-n-butyl ammonium tribromide

→

4′-benzoyloxy-2-bromoacetophenone

Yield 73.5%

Solvents

methanol

Conditions

Workup

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

Procedure

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).

Source