Hydrochloric Acid → 7-phenyl-3,4-dihydronaphthalene-2-carboxylic Acid

Temperature

0 °C

A mixture of sodium methoxide (18.3 g), dimethyl carbonate (107 ml) and 7-phenyl-1-tetralone (15.1 g) was refluxed for 30 minutes. The reaction mixture was cooled to 0° C. To the mixture was gradually added 3N hydrochloric acid (200 ml), and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with anhydrous sodium sulfate and concentrated under reduced pressure to give a brown solid. The solid was dissolved in dichloromethane (100 ml), and to the mixture was added sodium boron hydride (1.60 g) at 0° C. To the mixture was added dropwise methanol (10 ml) for 30 minutes, and the reaction mixture was stirred for 4 hours at 0° C. To the mixture was added water (500 ml), and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue was dissolved in methanol (45 ml). To the mixture was added 2N sodium hydroxide (50 ml), and the mixture was refluxed for 2 hours. The reaction mixture was cooled to room temperature, acidified with concentrated hydro-chloric acid and extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue was dissolved in Diglyme (1,1′-oxybis[2-methoxyethane]) (50 ml), and to the mixture was added concentrated hydrochloric acid (10 ml). The mixture was stirred for 2 hours at 100° C., and to the mixture was added water (500 ml). The mixture was extracted with ethyl acetate, and the organic layer was washed with saturated sodium chloride solution and concentrated under reduced pressure. The residue was dissolved in 1N sodium hydroxide (200 ml), washed with diethylether, acidified by adding concentrated hydrochloric acid to the aqueous layer and extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue was recrystallized from ethanol-water to give 7-phenyl-3,4-dihydronaphthalene-2-carboxylic acid (7.47 g) as brown crystals.

1. temperaturewas refluxed for 30 minutes
2. extractionthe mixture was extracted with ethyl acetate
3. washThe organic layer was washed with saturated sodium chloride solution
4. dry with materialdried with anhydrous sodium sulfate
5. concentrationconcentrated under reduced pressure
6. customto give a brown solid
7. extractionthe mixture was extracted with ethyl acetate
8. washThe organic layer was washed with saturated sodium chloride solution
9. dry with materialdried with anhydrous sodium sulfate
10. concentrationconcentrated under reduced pressure
11. dissolutionThe residue was dissolved in methanol (45 ml)
12. additionTo the mixture was added 2N sodium hydroxide (50 ml)
13. temperaturethe mixture was refluxed for 2 hours
14. temperatureThe reaction mixture was cooled to room temperature
15. extractionextracted with ethyl acetate
16. washThe organic layer was washed with saturated sodium chloride solution
17. dry with materialdried with anhydrous sodium sulfate
18. concentrationconcentrated under reduced pressure
19. dissolutionThe residue was dissolved in Diglyme (1,1′-oxybis[2-methoxyethane]) (50 ml)
20. additionto the mixture was added concentrated hydrochloric acid (10 ml)
21. stirringThe mixture was stirred for 2 hours at 100° C.
22. additionto the mixture was added water (500 ml)
23. extractionThe mixture was extracted with ethyl acetate
24. washthe organic layer was washed with saturated sodium chloride solution
25. concentrationconcentrated under reduced pressure
26. dissolutionThe residue was dissolved in 1N sodium hydroxide (200 ml)
27. washwashed with diethylether
28. additionby adding concentrated hydrochloric acid to the aqueous layer
29. extractionextracted with ethyl acetate
30. washThe organic layer was washed with saturated sodium chloride solution
31. dry with materialdried with anhydrous sodium sulfate
32. concentrationconcentrated under reduced pressure
33. customThe residue was recrystallized from ethanol-water

ORD record

ord-bee6762cdc664b3cae3be023635bdbe0

Source dataset

uspto-grants-2001_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06172061B2