Trifluoroacetic acid → 1-Cyano-5,6-dimethoxy-3-phenyl-3,4-dihydronaphthalene

Temperature

60 °C

To a suspension of 10 g (35 mmol) of 5,6-dimethoxy-3-phenyl 1,2,3,4-tetrahydro 1-naphthalenone, the product of Example 1, was added 7.5 g (75.6 mmol) of trimethylsilyl cyanide (commercially available from Aldrich Chemical Company) and approximately 50 mg of anhydrous aluminum chloride (AlCl3). The reaction mixture was heated at 60° C. for 3 h then cooled to ambient temperature and diluted with 150 mL of toluene. The volume of the reaction mixture was reduced in vacuo to approximately 50 mL. The resultant trimethylsilyl adduct was dehydrated by treatment with 15 mL of trifluoroacetic acid and 100 mg of p toluene sulfonic acid in 200 mL of toluene at reflux temperature for 1 h. The reaction mixture was cooled to ambient temperature, the layers separated and the organic layer washed with water, aqueous sodium bicarbonate solution and brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give a colorless oil. The oil was purified by column chromatography on silica gel eluted with 20% ethyl acetate in hexane to give 8.5 g (83% yield) of the title compound, m.p. 109°-110° C.

1. temperaturethen cooled to ambient temperature
2. temperatureat reflux temperature for 1 h
3. temperatureThe reaction mixture was cooled to ambient temperature
4. customthe layers separated
5. washthe organic layer washed with water, aqueous sodium bicarbonate solution and brine
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customto give a colorless oil
10. customThe oil was purified by column chromatography on silica gel
11. washeluted with 20% ethyl acetate in hexane

ORD record

ord-83f7f7823b92419f84af2826783355f9

Source dataset

uspto-grants-1990_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04963568