Reaktion #2700

Reaktionsgleichung

4-bromotoluene

3,4-dihydro-4,4-dimethyl-7-bromo-1(2H)-naphthalenone

Compound A

3,4-dihydro-4,4-dimethyl-7-bromo-1(2H)-naphthalenone

→

title compound

1-(Tol-4-yl)3,4-dihydro-4,4-dimethyl-7-bromo-naphthalene

Lösungsmittel

THF

THF

THF

ethylacetate

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated to 70° C. for 30 minutes
2. 2
   TemperaturAfter cooling to ambient temperature
3. 3
   Temperaturheated to 70° C. for 24 hours
4. 4
   TemperaturThe mixture was cooled to ambient temperature
5. 5
   Sonstigethe reaction was quenched by addition of H2O
6. 6
   workup.ADDITIONThe mixture was diluted with ether:ethylacetate (1:1, 100 mL)
7. 7
   Waschenwashed with saturated NH4Cl (15 mL), water (10 mL) and brine (10 mL)
8. 8
   TrocknenThe organic layer was dried with MgSO4
9. 9
   SonstigeSolvent was removed under reduced pressure
10. 10
    Sonstigeto afford the crude product as an off
11. 11
    Temperaturthe mixture was refluxed for 16 hours
12. 12
    TemperaturThe mixture was cooled to ambient temperature
13. 13
    Waschenwashed with 10% NaHCO3 (20 mL), brine (20 mL)
14. 14
    Trocknendried with MgSO4
15. 15
    Sonstigethe solvent wasremoved by evaporation
16. 16
    SonstigePurification by chromatography on silica gel

Vorschrift

To a mixture of Mg metal (650 mg, 27 mmol) in THF (20 mL) was added 4-bromotoluene (5.3 g, 31 mmol) in THF (40 mL). The mixture was stirred for 2 hours at ambient temperature and heated to 70° C. for 30 minutes. After cooling to ambient temperature, 3,4-dihydro-4,4-dimethyl-7-bromo-1(2H)-naphthalenone (Compound A) (2.1 g, 8 mmol), in THF (5 mL) was added and heated to 70° C. for 24 hours. The mixture was cooled to ambient temperature and the reaction was quenched by addition of H2O. The mixture was diluted with ether:ethylacetate (1:1, 100 mL) and washed with saturated NH4Cl (15 mL), water (10 mL) and brine (10 mL). The organic layer was dried with MgSO4. Solvent was removed under reduced pressure to afford the crude product as an off. The product was dissolved in THF (20 mL). To this solution p-toleune sulfonic acid (pTSA) (35 mg) was added and the mixture was refluxed for 16 hours. The mixture was cooled to ambient temperature, diluted with ethylacetate (160 mL), washed with 10% NaHCO3 (20 mL), brine (20 mL), dried with MgSO4 and the solvent wasremoved by evaporation. Purification by chromatography on silica gel gave the title compound as a white solid.

Quelle