Bromine → 2-Acetoxy-5-(2-bromoacetyl)benzyl acetate
Reaction equation
[Br:1]Br.[C:3]([O:6][CH2:7][C:8]1[CH:9]=[C:10]([C:18](=[O:20])[CH3:19])[CH:11]=[CH:12][C:13]=1[O:14][C:15](=[O:17])[CH3:16])(=[O:5])[CH3:4]>C(Cl)(Cl)Cl>[C:3]([O:6][CH2:7][C:8]1[CH:9]=[C:10]([C:18](=[O:20])[CH2:19][Br:1])[CH:11]=[CH:12][C:13]=1[O:14][C:15](=[O:17])[CH3:16])(=[O:5])[CH3:4]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of bromine (7.1 g.) in chloroform (20 ml.) was added dropwise to a stirred solution of 3'-acetoxymethyl-4'-acetoxyacetophenone (11.0 g.) in chloroform (150 ml.) at room temperature. After completion of the addition, the solution was washed with water (2×150 ml.) and brine (100 ml.). The organic phase was dried (MgSO4), filtered and evaporated to give 3'-acetoxymethyl-4'-acetoxy-2-bromoacetophenone (10.0 g.) which was judged to be sufficiently pure by IR and TLC [SiO2 ; 1:1 v/v EtOAc/petrol (60°-80° C.)] for use without further purification or characterisation. A solution of 3'-acetoxymethyl-4'-acetoxy-2-bromoacetophenone (10.0 g.) in dimethylsulphoxide (150 ml.) was stirred at room temperature for 48 hours. The solution was then poured into ice-water (500 ml.) and extracted with ethyl acetate (3×200 ml.). The organic layers were combined, dried (MgSO4) filtered. The solvent was removed by evaporation to give 3'-acetoxymethyl- 4'-acetoxy-phenylglyoxal hydrate as a yellow oil (6.5 g. 81%). The glyoxal derivative had a satisfactory IR spectrum and was judged pure by TLC (SiO2 : EtOAc) and was therefore used without full characterisation or isolation.
Workup
- additionAfter completion of the addition
- washthe solution was washed with water (2×150 ml.) and brine (100 ml.)
- dry with materialThe organic phase was dried (MgSO4)
- filtrationfiltered
- customevaporated
Sources & evidence
- ORD record
- ord-a4b0145af1f1473892e9a52510e414f7
- Source dataset
- uspto-grants-1983_12
- Patent number
- US04423070
Reaction notes
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