Methyl vinyl ketone → 6,8-Dimethyl-3-Acetyl-2H-Chromene

HRID 1110421Notes

Reaction equation

HRID 1110421 reaction equation
[OH:1][C:2]1[C:9]([CH3:10])=[CH:8][C:7]([CH3:11])=[CH:6][C:3]=1[CH:4]=O.[O:12]=[C:13]([CH3:16])[CH:14]=[CH2:15].C(=O)([O-])[O-].[K+].[K+]>CC(=O)CC>[CH3:11][C:7]1[CH:6]=[C:3]2[C:2](=[C:9]([CH3:10])[CH:8]=1)[O:1][CH2:15][C:14]([C:13](=[O:12])[CH3:16])=[CH:4]2

Participants

5

Reactant 3

HCID 6570Methyl vinyl ketoneHCID 11430Potassium CarbonateHCID 47702452-Hydroxy-3,5-dimethylbenzaldehyde

Product 1

HCID 144791196,8-Dimethyl-3-Acetyl-2H-Chromene

Reagents, catalysts & solvents 1

HCID 6569Methyl Ethyl KetoneSolvent

Procedure

1.50 g (10 mmol) of 2-hydroxy-3,5-dimethylbenzaldehyde together with 0.66 g (10 mmol) of 3-oxo-1-butene are added at room temperature to a suspension of 0.14 g (1 mmol) of potassium carbonate in 50 ml of 2-butanone. The mixture is brought to reflux with stirring and this temperature is maintained for 90 minutes. The reaction medium is evaporated on a water bath under vacuum, and the residue is taken up with 100 ml of water and extracted 3 times with 75 ml of diethyl ether. The organic phases are combined, washed to neutrality with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and evaporated on a water bath under vacuum, and chromatographed on a column of silica (70-230 mesh), eluting with dichloromethane.

Workup

  1. temperatureto reflux
  2. temperaturethis temperature is maintained for 90 minutes
  3. customThe reaction medium is evaporated on a water bath under vacuum
  4. extractionextracted 3 times with 75 ml of diethyl ether
  5. washwashed to neutrality with saturated aqueous sodium chloride solution
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. customevaporated on a water bath under vacuum
  9. customchromatographed on a column of silica (70-230 mesh)
  10. washeluting with dichloromethane

Sources & evidence

ORD record
ord-9b62a6e069564e71b0ea06e80576b4ef
Source dataset
uspto-grants-1990_12
Patent number
US04975454

Reaction notes

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