Hydrogen Peroxide → 4,4-Dimethyl-1,2,3,4-tetrahydronaphthalen-2-one

HRID 1654331Notes

Reaction equation

HRID 1654331 reaction equation
[OH:1]O.[CH3:3][C:4]1([CH3:14])[C:13]2[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=2)[CH:7]=[CH:6][CH2:5]1>C(O)=O>[CH3:3][C:4]1([CH3:14])[C:13]2[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=2)[CH2:7][C:6](=[O:1])[CH2:5]1

Participants

4

Reactant 2

HCID 784Hydrogen PeroxideHCID 127728391,2-Dihydro-1,1-dimethylnaphthalene

Product 1

HCID 127728434,4-Dimethyl-1,2,3,4-tetrahydronaphthalen-2-oneYield 40%

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

Procedure

To a stirred mixture of 30% hydrogen peroxide (5 ml) and 97% formic acid (20 ml) in a round bottom flask equipped with an additional funnel, thermometer, and an ice water bath was added 1,2-dihydro-1,1-dimethylnaphthalene (4.5 g, 28 mmoles) dropwise at 5° C. under a nitrogen atmosphere. When the addition was complete, the reaction vessel was raised above the cooling bath to allow the reaction temperature to rise to just below 35° C. at which point the flask was immersed again. In this manner the temperature of the reaction was maintained between 30° and 35° C. for 45 minutes. After this time the exothermic phase of the reaction ended and the mixture was allowed to cool to room temperature. A solution of 10% aqueous ferric sulfate was added in portions of a few milliliters each until cloudiness persisted in the stired mixture and then all solvent was removed under reduced pressure. The viscous brown residue was refluxed with 20% H2SO4 (20 ml) for 4 hours and then cooled, extracted three times with ether (75 ml each), dried over magnesium sulfate, filtered and evaporated to leave a brown oil. This was purified using silica gel column chromatography eluting with ethyl acetate:hexane (7:93) to give 4,4-dimethyl-2-tetralone. (3.4 g, 74%). Overall yield=40%.

Workup

  1. customequipped with an additional funnel
  2. additionWhen the addition
  3. temperaturethe reaction vessel was raised above the cooling bath
  4. customto rise to just below 35° C. at which point
  5. temperatureIn this manner the temperature of the reaction was maintained between 30° and 35° C. for 45 minutes
  6. customall solvent was removed under reduced pressure
  7. temperatureThe viscous brown residue was refluxed with 20% H2SO4 (20 ml) for 4 hours
  8. temperaturecooled
  9. extractionextracted three times with ether (75 ml each)
  10. dry with materialdried over magnesium sulfate
  11. filtrationfiltered
  12. customevaporated
  13. customto leave a brown oil
  14. customThis was purified
  15. washeluting with ethyl acetate:hexane (7:93)

Sources & evidence

ORD record
ord-687e84e2bb1e40a29006c4472ec674fe
Source dataset
uspto-grants-1995_04
Patent number
US05405851

Reaction notes

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