Sulfuric Acid → 7-Methoxy-4,4-dimethylchroman-2-one

HRID 1350874Notes

Reaction equation

HRID 1350874 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([OH:9])[CH:6]=[CH:7][CH:8]=1.S(=O)(=O)(O)O.[CH3:15][C:16]([CH3:22])=[CH:17][C:18](OC)=[O:19]>C(OCC)(=O)C>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:6]([C:16]([CH3:22])([CH3:15])[CH2:17][C:18](=[O:19])[O:9]2)=[CH:7][CH:8]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 90073-MethoxyphenolHCID 13546Methyl 3-methyl-2-butenoate

Product 1

HCID 210975117-Methoxy-4,4-dimethylchroman-2-oneYield 39%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
130 °C

Procedure

A mixture of 3-methoxy-phenol (12 g, 96.5 mmol) and conc. sulfuric acid (0.5 ml) was heated at 130° C. with stirring, and methyl 3,3-dimethylacrylate (5.8 g, 51 mmol) was added. The mixture was stirred at 13° C. for 3 hours. After being cooled to ambient temperature, the organic layer was dissolved in ethyl acetate. The organic layer washed with brine, dried over sodium sulfate. After filtration to separate solvent and sodium sulfate, the solvent was removed under reduced pressure to give a residue, which was applied to a silica gel chromatography column and eluted with ethyl acetate/hexane= 1/9 to furnish 4.1 g (39% yield) of the title compound as a brown solid.

Workup

  1. stirringThe mixture was stirred at 13° C. for 3 hours
  2. temperatureAfter being cooled to ambient temperature
  3. washThe organic layer washed with brine
  4. dry with materialdried over sodium sulfate
  5. filtrationAfter filtration
  6. customto separate solvent and sodium sulfate
  7. customthe solvent was removed under reduced pressure
  8. customto give a residue, which
  9. washeluted with ethyl acetate/hexane= 1/9

Sources & evidence

ORD record
ord-1eac91c7996749c2b81e205a86e7af30
Source dataset
uspto-grants-2007_05
Patent number
US07214824B2

Reaction notes

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