Reaktion #6483

Reaktionsgleichung

Trimethylsilylcyanide

6-methoxy-α-tetralone

Lithium cyanide

→

title compound

Ausbeute 60.4%

1-Cyano-6-methoxy-3,4-dihydronaphthalene

Ausbeute 60.4%

Lösungsmittel

tetrahydrofuran

N,N-dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe THF was removed under reduced pressure
2. 2
   SonstigeThe concentrate was partitioned between diethyl ether and water (5:1 v/v)
3. 3
   ExtraktionThe aqueous layer was extracted with diethyl ether
4. 4
   Extraktionthe combined organic extract
5. 5
   Waschenwas washed with brine
6. 6
   Trocknendried over anhydrous magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under reduced pressure
9. 9
   workup.DISSOLUTIONThe residue was dissolved in 400 mL of anhydrous toluene
10. 10
    workup.ADDITIONcontaining 15 g of p-toluenesulfonic acid
11. 11
    Temperaturpreviously refluxed in order
12. 12
    Sonstigeto remove residual water
13. 13
    workup.DISTILLATIONby azeotropic distillation
14. 14
    TemperaturThe mixture was heated
15. 15
    Temperaturat reflux (with a Dean Stark trap) for 1 h
16. 16
    TemperaturThe resultant solution was cooled to ambient temperature
17. 17
    Waschenwashed with cold 1N aqueous sodium hydroxide solution
18. 18
    SonstigeThe organic layer was separated
19. 19
    Trocknendried over anhydrous magnesium sulfate
20. 20
    Filtrationfiltered
21. 21
    Einengenconcentrated in vacuo
22. 22
    SonstigeThe residue was purified on silica gel
23. 23
    Wascheneluted with 10% ethyl acetate in hexane

Vorschrift

Trimethylsilylcyanide (50.0 g, 510 mmol) was added to a suspension of 75.0 g (430 mmol) of 6-methoxy-α-tetralone (commercially available from Aldrich Chemical Company) in 75 mL of anhydrous tetrahydrofuran (THF) at ambient temperature. Lithium cyanide (100 mL of a 0.5M solution in N,N-dimethylformamide (DMF) was added to the resultant mixture in one portion. The reaction mixture was stirred at ambient temperature for 1.5 h and then the THF was removed under reduced pressure. The concentrate was partitioned between diethyl ether and water (5:1 v/v). The aqueous layer was extracted with diethyl ether and the combined organic extract was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was dissolved in 400 mL of anhydrous toluene, containing 15 g of p-toluenesulfonic acid, previously refluxed in order to remove residual water by azeotropic distillation. The mixture was heated at reflux (with a Dean Stark trap) for 1 h. The resultant solution was cooled to ambient temperature and washed with cold 1N aqueous sodium hydroxide solution. The organic layer was separated, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified on silica gel eluted with 10% ethyl acetate in hexane to afford 48.09 g (60% yield) of the title compound. The physical properties of the product were identical to the properties reported for this compound by F. Z. Basha, et al. in J. Organic Chemistry, 50: 4160-2 (1985).

Quelle