Potassium Persulfate → 4-Bromo-2,3-dihydro-2,2-dimethyl-3-benzofuranone

HRID 726614Notes

Reaction equation

HRID 726614 reaction equation
[Br:1][C:2]1[C:7]2[CH2:8][C:9]([CH3:12])([CH3:11])[O:10][C:6]=2[CH:5]=[CH:4][CH:3]=1.S(OOS([O-])(=O)=O)([O-])(=O)=[O:14].[K+].[K+]>O.C(#N)C.O.O.O.O.O.S([O-])([O-])(=O)=O.[Cu+2]>[Br:1][C:2]1[C:7]2[C:8](=[O:14])[C:9]([CH3:12])([CH3:11])[O:10][C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 2

HCID 24412Potassium PersulfateHCID 539891274-Bromo-2,2-dimethyl-2,3-dihydrobenzofuran

Product 1

HCID 543779064-Bromo-2,3-dihydro-2,2-dimethyl-3-benzofuranoneYield 67%

Reagents, catalysts & solvents 3

HCID 24463Copper sulfate pentahydrateCatalystHCID 962WaterSolvent2×HCID 6342AcetonitrileSolvent

Procedure

Under a nitrogen atmosphere, a stirred solution of 3.0 grams (0.013 mole) 4-bromo-2,3-dihydro-2,2-dimethylbenzofuran, 10.7 grams (0.039 mole) of potassium persulfate, and 3.3 grams (0.013 mole) of copper(11) sulfate pentahydrate in 30 mL of water and 30 mL of acetonitrile is heated at reflux for one hour. After this time the reaction mixture is poured into 200 mL of water. The mixture is then extracted with one 200 mL portion of diethyl ether. The extract is dried with magnesium sulfate and filtered. The filtrate is concentrated under reduced pressure to a residual oil. The oil is subjected to column chromatography on silica gel. During is accomplished using 1:1 petroleum ether and methylene chloride. The product-containing fractions are combined and concentrated under reduced pressure, yielding 2.1 grams of 4-bromo-2,3-dihydro-2,2-dimethyl-3-benzofuranone. The NMR spectrum is consistent with the proposed structure.

Workup

  1. temperatureat reflux for one hour
  2. extractionThe mixture is then extracted with one 200 mL portion of diethyl ether
  3. dry with materialThe extract is dried with magnesium sulfate
  4. filtrationfiltered
  5. concentrationThe filtrate is concentrated under reduced pressure to a residual oil
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-3f2003143bb24ca79aec3fdcbfe9db40
Source dataset
uspto-grants-1998_01
Patent number
US05710157

Reaction notes

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