Boron trifluoride etherate → 2-Acetyl-7-methoxy-3,4-dihydro-2H-naphthalen-1-one

HRID 598768Notes

Reaction equation

HRID 598768 reaction equation
B(F)(F)F.[CH3:5][CH2:6][O:7]CC.[CH3:10][O:11][C:12]1[CH:21]=[C:20]2[C:15]([CH2:16][CH2:17][CH2:18][C:19]2=[O:22])=[CH:14][CH:13]=1>C(OC(=O)C)(=O)C>[C:6]([CH:18]1[CH2:17][CH2:16][C:15]2[C:20](=[CH:21][C:12]([O:11][CH3:10])=[CH:13][CH:14]=2)[C:19]1=[O:22])(=[O:7])[CH3:5]

Participants

4

Reactant 2

HCID 8000Boron trifluoride etherateHCID 812767-Methoxy-1,2,3,4-tetrahydronaphthalen-1-one

Product 1

HCID 190953982-Acetyl-7-methoxy-3,4-dihydro-2H-naphthalen-1-one

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

Boron trifluoride etherate (0.53 mL) was added dropwise to a stirred mixture of 7-methoxytetralone (176 mg, 1 mmol) in acetic anhydride (1.8 mL). The reaction was stirred at room temperature for 2 hours, then poured into ice-water and stirred for 1 hour. The mixture was extracted with ether, and the ether extracts were evaporated. The residue was diluted with methanol (12 mL) and saturated sodium acetate (8 mL) and stirred at reflux for 4 hours. After cooling to room temperature, the solution was extracted with dichloromethane. The organic extracts were washed with brine, dried over MgSO4, and concentrated. SiO2 chromatography with 5-20% ethyl acetate/hexanes gave 72.5 mg of the desired product. LC-MS (C13H14O3 calculated 218) m/z 217 (M−H).

Workup

  1. stirringstirred for 1 hour
  2. extractionThe mixture was extracted with ether
  3. customthe ether extracts were evaporated
  4. additionThe residue was diluted with methanol (12 mL) and saturated sodium acetate (8 mL)
  5. stirringstirred
  6. temperatureat reflux for 4 hours
  7. temperatureAfter cooling to room temperature
  8. extractionthe solution was extracted with dichloromethane
  9. washThe organic extracts were washed with brine
  10. dry with materialdried over MgSO4
  11. concentrationconcentrated

Sources & evidence

ORD record
ord-a77f9f0a61434ed4a9b5e3ae860086e5
Source dataset
uspto-grants-2011_03
Patent number
US07897634B2

Reaction notes

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