6-Methoxy-alpha-tetralone → 6-Methoxynaphthalen-1-ol

HRID 2086122Notes

Reaction equation

HRID 2086122 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9](=[O:13])[CH2:8][CH2:7][CH2:6]2>[Pd].CC1C=CC(C(C)C)=CC=1>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9]([OH:13])=[CH:8][CH:7]=[CH:6]2

Participants

4

Reactant 1

HCID 141126-Methoxy-alpha-tetralone

Product 1

HCID 110084166-Methoxynaphthalen-1-olYield 83%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 7463P-CymeneSolvent

Procedure

A mixture of 6-methoxy-1-tetralone (20.84 g, 118.3 mmol), 10% Pd/C (10.1 g), and p-cymene (500 mL) was heated at reflux for 60 hours. The suspension was cooled to room temperature and filtered through Celite. The solid was washed with ethyl acetate until UV clear and the combined organic solution was extracted with 1 N sodium hydroxide (3×200 mL). The combined aqueous layers were made acidic with 6N HCl and extracted with ethyl acetate (3×300 mL). The combined organic layers were dried over magnesium sulfate and filtered. Evaporation of the solvent and purification on a silica column (25% ethyl acetate-hexanes) yielded 17.02 g (83%) of the title compound as a light brown solid. An analytical sample was prepared by purification on a second silica column (40-60% dichloromethane-hexanes) to yield a white solid: mp 73-75° C.; 1H NMR (DMSO-d6): δ 3.85 (3H, s), 6.70-6.74 (1H, m), 7.06 (1H, dd, J=2.34 Hz, J=9.15 Hz), 7.20-7.27 (3H, m), 8.02 (1H, d, J=9.12 Hz), 10.01 (1H, s); MS (ESI) m/z174 (M-H)−.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 60 hours
  3. filtrationfiltered through Celite
  4. washThe solid was washed with ethyl acetate until UV clear
  5. extractionthe combined organic solution was extracted with 1 N sodium hydroxide (3×200 mL)
  6. extractionextracted with ethyl acetate (3×300 mL)
  7. dry with materialThe combined organic layers were dried over magnesium sulfate
  8. filtrationfiltered
  9. customEvaporation of the solvent and purification on a silica column (25% ethyl acetate-hexanes)

Sources & evidence

ORD record
ord-4e784939a79e4623b1c888e9427ce913
Source dataset
uspto-grants-2004_04
Patent number
US06723747B2

Reaction notes

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