5-(4-Bromo-2,6-dimethylphenyl)-4-hydroxycyclopent-2-enone → 2-(4-Bromo-2,6-dimethylphenyl)cyclopent-4-ene-1,3-dione

HRID 1193027Notes

Reaction equation

HRID 1193027 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([CH3:8])[C:5]([CH:9]2[C:13](=[O:14])[CH:12]=[CH:11][CH:10]2[OH:15])=[C:4]([CH3:16])[CH:3]=1.CC(C)=O.OS(O)(=O)=O.O=[Cr](=O)=O>CC(C)=O>[Br:1][C:2]1[CH:3]=[C:4]([CH3:16])[C:5]([CH:9]2[C:13](=[O:14])[CH:12]=[CH:11][C:10]2=[O:15])=[C:6]([CH3:8])[CH:7]=1

Participants

4

Reactant 2

HCID 580708555-(4-Bromo-2,6-dimethylphenyl)-4-hydroxycyclopent-2-enoneHCID 131709961Jones' reagent

Product 1

HCID 497653832-(4-Bromo-2,6-dimethylphenyl)cyclopent-4-ene-1,3-dioneYield 94.8%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a solution of 5-(4-bromo-2,6-dimethylphenyl)-4-hydroxycyclopent-2-enone (18.33 g. 65 mmol) in acetone (200 ml) at 0° C. is added, dropwise, a solution of Jones reagent (1.67 M, 39 ml, 65 mmol) and the resulting yellow solution is stirred at 0° C. for 90 minutes. The reaction is quenched by the addition of propan-2-ol (1 ml) and stirred for a further 2 hours. Brine (300 ml) is added and the reaction is extracted with ethyl acetate (3×250 ml). The organic extracts are combined, washed with brine, dried over anhydrous magnesium sulfate, filtered and the filtrate is concentrated under reduced pressure. The residue is purified by column chromatography on silica gel to give 2-(4-bromo-2,6-dimethylphenyl)cyclopent-4-ene-1,3-dione (17.2 g).

Workup

  1. customThe reaction is quenched by the addition of propan-2-ol (1 ml)
  2. additionBrine (300 ml) is added
  3. extractionthe reaction is extracted with ethyl acetate (3×250 ml)
  4. washwashed with brine
  5. dry with materialdried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. concentrationthe filtrate is concentrated under reduced pressure
  8. customThe residue is purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-25cb82c3ebe64374b209fef3be8ccadf
Source dataset
uspto-grants-2014_03
Patent number
US08680339B2

Reaction notes

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