Reacción #2700

Ecuación de reacción

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

Disolventes

THF

THF

THF

ethylacetate

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaheated to 70° C. for 30 minutes
2. 2
   TemperaturaAfter cooling to ambient temperature
3. 3
   Temperaturaheated to 70° C. for 24 hours
4. 4
   TemperaturaThe mixture was cooled to ambient temperature
5. 5
   Otrothe reaction was quenched by addition of H2O
6. 6
   workup.ADDITIONThe mixture was diluted with ether:ethylacetate (1:1, 100 mL)
7. 7
   Lavadowashed with saturated NH4Cl (15 mL), water (10 mL) and brine (10 mL)
8. 8
   SecadoThe organic layer was dried with MgSO4
9. 9
   OtroSolvent was removed under reduced pressure
10. 10
    Otroto afford the crude product as an off
11. 11
    Temperaturathe mixture was refluxed for 16 hours
12. 12
    TemperaturaThe mixture was cooled to ambient temperature
13. 13
    Lavadowashed with 10% NaHCO3 (20 mL), brine (20 mL)
14. 14
    Secadodried with MgSO4
15. 15
    Otrothe solvent wasremoved by evaporation
16. 16
    OtroPurification by chromatography on silica gel

Procedimiento

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.

Fuente