Methanol → 6-Bromo-4-tert-butyl-1,1-dimethyl-1,2-dihydronaphthalene

Temperatur

-20 °C

In a flame dried round bottom flask 7-bromo-3,4-dihydro-4,4-dimethylnaphthalen-1(2H)-one (Compound G, 2.0 g, 7.93 mmol) was dissolved in anhydrous THF (50 ml) and 3,4,5,6,-tetrahydro-2(H)-pyrimidinone (DMPU) (11.5 ml, 95.16 mmol) was added, under argon atmosphere. The reaction was then cooled to −20° C. and a solution of t-butyl magnesium chloride (16 ml, 31.7 mmol) (2 M in Et2O) was added dropwise and stirred at −20° C. for 2 h and at ambient temperature for 1 h, under argon atmosphere. The reaction was quenched at 0° C. with saturated ammonium chloride solution (20 ml) and extracted with EtOAc (2×50 ml). The combined extract was washed with water (20 ml), brine (20 ml) and dried over MgSO4. The solvent was evaporated under reduced pressure to afford a yellow oil. To this yellow oil were added MeOH (50 ml) and p-tolylsulfonic acid (100 mg). The resultant reaction solution was heated in an oil bath (60° C.) for 3 h. The reaction was cooled and quenched with water (20 ml), extracted with EtOAc (2×(50 ml). The combined extract was washed with saturated NaHCO3 (20 ml), water (20 ml), brine (20 ml), and dried over MgSO4. The solvent was concentrated in vacuo and the title compound was obtained as a colorless oil after purification by flash chromatography (silica, hexane).

1. customThe reaction was quenched at 0° C. with saturated ammonium chloride solution (20 ml)
2. extractionextracted with EtOAc (2×50 ml)
3. extractionThe combined extract
4. washwas washed with water (20 ml), brine (20 ml)
5. dry with materialdried over MgSO4
6. customThe solvent was evaporated under reduced pressure
7. customto afford a yellow oil
8. customThe resultant reaction solution
9. temperaturewas heated in an oil bath (60° C.) for 3 h
10. temperatureThe reaction was cooled
11. customquenched with water (20 ml)
12. extractionextracted with EtOAc (2×(50 ml)
13. extractionThe combined extract
14. washwas washed with saturated NaHCO3 (20 ml), water (20 ml), brine (20 ml)
15. dry with materialdried over MgSO4
16. concentrationThe solvent was concentrated in vacuo

ORD-Eintrag

ord-45a6879d252e405b83a8de53d2c24000

Quelldatensatz

uspto-grants-2005_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06855832B2