Trifluoroacetic acid → 1-Cyano-5,6-dimethoxy-3-phenyl-3,4-dihydronaphthalene

HRID 54142Notes

Reaction equation

HRID 54142 reaction equation
[CH3:1][O:2][C:3]1[C:12]([O:13][CH3:14])=[CH:11][CH:10]=[C:9]2[C:4]=1[CH2:5][CH:6]([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[CH2:7][C:8]2=O.C[Si]([C:26]#[N:27])(C)C.FC(F)(F)C(O)=O>C1(C)C=CC=CC=1.[Cl-].[Al+3].[Cl-].[Cl-].C1(C)C=CC(S(O)(=O)=O)=CC=1>[C:26]([C:8]1[C:9]2[C:4](=[C:3]([O:2][CH3:1])[C:12]([O:13][CH3:14])=[CH:11][CH:10]=2)[CH2:5][CH:6]([C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=2)[CH:7]=1)#[N:27]

Participants

7

Reactant 3

HCID 6422Trifluoroacetic acidHCID 82115Trimethylsilyl cyanideHCID 124785445,6-Dimethoxy-3-phenyl-3,4-dihydronaphthalen-1(2H)-one

Product 1

HCID 199611621-Cyano-5,6-dimethoxy-3-phenyl-3,4-dihydronaphthaleneYield 83.4%

Reagents, catalysts & solvents 3

HCID 6101p-Toluenesulfonic acidCatalystHCID 6451240Aluminum(III) ChlorideCatalystHCID 1140TolueneSolvent2×

Conditions

Temperature
60 °C

Procedure

To a suspension of 10 g (35 mmol) of 5,6-dimethoxy-3-phenyl-1,2,3,4-tetrahydronaphthalen-1-one, the product of Example 1, was added 7.5 g (75.6 mmol) of trimethylsilyl cyanide (commercially available from Aldrich Chemical Company) and approximately 50 mg of anhydrous aluminum chloride (AlCl3). The reaction mixture was heated at 60° C. for 3 h then cooled to ambient temperature and diluted with 150 mL of toluene. The volume of the reaction mixture was reduced in vacuo to approximately 50 mL. The resultant trimethylsilyl adduct was dehydrated by treatment with 15 mL of trifluoroacetic acid and 100 mg of p-toluenesulfonic acid in 200 mL of toluene at reflux temperature for 1 h. The reaction mixture was cooled to ambient temperature, the layers separated and the organic layer washed with water, aqueous sodium bicarbonate solution and brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to a colorless oil. The oil was purified by column chromatography on silica gel eluted with 20% ethyl acetate in hexane to give 8.5 g (83% yield) of the title compound, m.p. 109°-110° C.

Workup

  1. temperaturethen cooled to ambient temperature
  2. temperatureat reflux temperature for 1 h
  3. temperatureThe reaction mixture was cooled to ambient temperature
  4. customthe layers separated
  5. washthe organic layer washed with water, aqueous sodium bicarbonate solution and brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated under reduced pressure to a colorless oil
  9. customThe oil was purified by column chromatography on silica gel
  10. washeluted with 20% ethyl acetate in hexane

Sources & evidence

ORD record
ord-ea6a830fbaa945c5afc4edc6508e072c
Source dataset
uspto-grants-1997_04
Patent number
US05621133

Reaction notes

Loading…