Boron trifluoride etherate → 5,6-Dimethoxy-3,4-dihydronaphthalene-1-carbonitrile

HRID 2199534Notes

Reaction equation

HRID 2199534 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][CH2:6][CH2:7][C:8]2=O.[Si]([C:20]#[N:21])(C)(C)C.B(F)(F)F.CCOCC>C1(C)C=CC=CC=1>[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][CH2:6][CH:7]=[C:8]2[C:20]#[N:21]

Participants

5

Reactant 3

HCID 8000Boron trifluoride etherateHCID 82115Trimethylsilyl cyanideHCID 82192465,6-dimethoxy-1-tetralone

Product 1

HCID 135385495,6-Dimethoxy-3,4-dihydronaphthalene-1-carbonitrileYield 96%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Tetralone 7 (1.7 g, 8.25 mmol) was added as a slurry in freshly distilled toluene (25 mL) to a dried flask with magnetic stirring. TMSCN (1.42 mL, 10.7 mmol) was added dropwise. After stirring for 10 min, BF3.OEt2 (1.57 mL, 12.38 mmol) was added with a syringe. The reaction was stirred at room temperature for 3 h, until no starting material remained. The reaction was quenched by pouring over 30 mL ice water and stirring vigorously. To this aqueous mixture were added 20 mL of Et2O, and the layers were separated. The aqueous layer was extracted twice more with Et2O and once with EtOAc. The combined organic layers were dried over Na2SO4, filtered, and evaporated under reduced pressure to afford a tan solid (1.7 g, 7.9 mmol, 96%) that was recrystallized from MeOH to yield fine, colorless needles; mp 138-140° C. (lit.36 mp 137-139° C.). 1H NMR: (300 MHz, CDCl3): δ 7.18 (d, 1H, J=8 Hz, ArH); 6.80 (d, 1H, J=8 Hz, ArH); 6.75 (t, 1H, J=4.6 Hz, ArCH2CH2CH); 3.88 (s, 3H, ArOCH3); 3.76 (s, 3H, ArOCH3); 2.87 (t, 2H, J=8 Hz, ArCH2); 2.44 (m, 2H, ArCH2CH2). EIMS (M+)=215.

Workup

  1. stirringThe reaction was stirred at room temperature for 3 h, until no starting material
  2. customThe reaction was quenched
  3. additionby pouring over 30 mL ice water
  4. stirringstirring vigorously
  5. additionTo this aqueous mixture were added 20 mL of Et2O
  6. customthe layers were separated
  7. extractionThe aqueous layer was extracted twice more with Et2O and once with EtOAc
  8. dry with materialThe combined organic layers were dried over Na2SO4
  9. filtrationfiltered
  10. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-ed83d81b65fc495baa3ad821c24cf8b7
Source dataset
uspto-grants-2016_06
Patent number
US09359303B2

Reaction notes

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