1,2-Dichloroethane → 5,6,7,8-Tetrahydro-3-hydroxy-5,5,8,8-tetramethyl-2-naphthyl methyl ketone

HRID 1265250Notes

Reaction equation

HRID 1265250 reaction equation
O[C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)C=CC=1.[C:12](Cl)(=[O:14])[CH3:13].[Cl-].[Al+3].[Cl-].[Cl-].O=[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]1[OH:27].Cl[CH2:29]CCl>CO.CCOC(C)=O.CCCCCC.CCOC(C)=O>[OH:27][C:22]1[C:21]([C:12](=[O:14])[CH3:13])=[CH:26][C:25]2[C:8]([CH3:7])([CH3:29])[CH2:9][CH2:10][C:11]([CH3:2])([CH3:6])[C:24]=2[CH:23]=1

Participants

9

Reactant 5

HCID 111,2-DichloroethaneHCID 6367Acetyl chlorideHCID 70051-NaphtholHCID 440554Cyclohexadienone, hydroxy-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 2266995,6,7,8-Tetrahydro-3-hydroxy-5,5,8,8-tetramethyl-2-naphthyl methyl ketone

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 8857Ethyl AcetateSolventHCID 21226206Ethyl acetate hexaneSolvent

Conditions

Temperature
25 °C

Procedure

The hydroxynaphthalene (19.1 g, 93.6 mmol) was treated dropwise with acetyl chloride (7.7 g, 98.2 mmol) in 1,2-dichloroethane (250 ml) at 0° C. After completion of the addition, aluminum chloride (10 g, 75.2 mmol) was added in portions over 5 min. The mixture was heated at reflux for 10 h, then stirred at 25° C. for 8 h. GC analysis indicated the desired keto-phenol was present in 98.6% purity. The reaction mixture was poured onto ice water and aqueous work-up (EtOAc extraction) gave a brown-black solid, which was dissolved in hot methanol, filtered, and concentrated to give a brown viscous semi-solid. Flash chromatography (15% EtOAc/hexane) gave 1-(3-hydroxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)ethanone as a light yellow solid. Recrystallization from hexane afforded the product as white crystals 15.2 g (66%): 1H NMR (400 MHz, CDCl3) δ 7.63 (s, 1H, ArH), 6.9 (s, 1H, ArH), 2.61 (s, 3H, CH3), 1.67 (s, 4H, 2CH2), 1.29 (s, 6H, 2CH3), 1.27 (s, 6H, 2CH3).

Workup

  1. additionwas added in portions over 5 min
  2. temperatureThe mixture was heated
  3. temperatureat reflux for 10 h
  4. customgave a brown-black solid, which
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give a brown viscous semi-solid

Sources & evidence

ORD record
ord-3487edf8b63d4b7c92a1b9c20891cb19
Source dataset
uspto-grants-2003_04
Patent number
US06545049B1

Reaction notes

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