Hydrochloric Acid → 1-Tetralone

HRID 1992863Notes

Reaction equation

HRID 1992863 reaction equation
[CH3:1][CH:2]([CH:4]1[CH2:13][C:12]2[C:7](=[CH:8][CH:9]=[C:10]([O:14][CH3:15])[CH:11]=2)[C:6](=[O:16])[CH2:5]1)[CH3:3].[Br:17]Br.C1CCN2C(=NCCC2)CC1.Cl>C(Cl)Cl.CC#N.[Cl-].[Na+].O>[C:6]1(=[O:16])[C:7]2[C:12](=[CH:11][CH:10]=[CH:9][CH:8]=2)[CH2:13][CH2:4][CH2:5]1.[Br:17][C:5]1[C:4]([CH:2]([CH3:1])[CH3:3])=[CH:13][C:12]2[C:7](=[CH:8][CH:9]=[C:10]([O:14][CH3:15])[CH:11]=2)[C:6]=1[OH:16]

Participants

9

Reactant 4

HCID 313Hydrochloric AcidHCID 24408BromineHCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 68536766HCID 68536766, compound

Product 2

HCID 107241-TetraloneHCID 68536740HCID 68536740, compound

Reagents, catalysts & solvents 3

HCID 6342AcetonitrileSolventHCID 6344DichloromethaneSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

To a solution of 3-(1-methylethyl)-6-(methyloxy)-3,4-dihydro-1(2H)-naphthalenone (68) (0.40 g, 1.83 mmol) in CH2CO2 (15 mL) was added a solution of bromine (0.59 g, 3.68 mmol) in CH2Cl2 (5 mL). The mixture was stirred at room temperature overnight. Volatiles were removed under vacuum at room temperature. The residue was dissolved in CH3CN (15 mL), cooled in an acetone-ice bath, DBU (0.44 g, 2.75 mmol) in CH3CN (2 mL) was added dropwise. The resulting mixture was allowed to warm up to room temperature and stirred for 1 h. 5 N HCl (1 mL) was added followed by brine (50 mL), and the mixture was extracted with CH2Cl2. The extracts were combined and washed with brine, dried over Na2SO4, filtered, and the filtrate was concentrated to give the crude product as a brown oil. The crude product was purified by flash chromatography over SiO2 with hexanes:EtOAc (25:1) to give 0.43 g (79% from tetralone) of the title compound (69) as a colorless viscous oil. 1H NMR (400 MHz, CDCl3): δ 1.32 (d, J=6.8 Hz, 6H), 3.35 (sept, J=6.8 Hz, 1H), 3.91 (s, 3H), 6.11 (s, 1H), 7.04 (d, J=2.4 Hz, 1H), 7.08 (dd, J1=9.1 Hz, J2=2.5 Hz, 1H), 7.21 (s, 1H), 8.08 (d, J=9.1 Hz, 1H).

Workup

  1. customVolatiles were removed under vacuum at room temperature
  2. dissolutionThe residue was dissolved in CH3CN (15 mL)
  3. temperaturecooled in an acetone-ice bath
  4. temperatureto warm up to room temperature
  5. stirringstirred for 1 h
  6. extractionthe mixture was extracted with CH2Cl2
  7. washwashed with brine
  8. dry with materialdried over Na2SO4
  9. filtrationfiltered
  10. concentrationthe filtrate was concentrated
  11. customto give the crude product as a brown oil
  12. customThe crude product was purified by flash chromatography over SiO2 with hexanes:EtOAc (25:1)

Sources & evidence

ORD record
ord-1e4ce0ab09b84880a6a537e25f7be6f5
Source dataset
uspto-grants-2010_01
Patent number
US07649093B2

Reaction notes

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