反应详情

2-(4′-Ethoxy-2,2′,3,3′-tetrafluorobiphenyl-4-yl)acetoaldehyde (9) (17.2 g) prepared in the seventh step was dissolved in acetone (150 ml) and the solution was cooled on an ice bath. The Jones reagent (2.67M; 35 ml) was added to the solution. After 2 hours of stirring, isopropyl alcohol (10 ml) was added, and the stirring was continued for 30 minutes. The reaction mixture was filtered through Celite, and water (200 ml) and ethyl acetate (100 ml) were added to filtrate to give two layers. The water layer was extracted with ethyl acetate (50 ml) three times, and the combined organic layer was washed with water. The solution was dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure. The residue was purified by means of back-extraction to give 2-(4′-ethoxy-2,2′,3,3′-tetrafluorobiphenyl-4-yl)acetic acid (10) (13.6 g) in 75.2% yield.

1. temperaturethe solution was cooled on an ice bath
2. waitthe stirring was continued for 30 minutes
3. filtrationThe reaction mixture was filtered through Celite, and water (200 ml) and ethyl acetate (100 ml)
4. additionwere added to filtrate
5. customto give two layers
6. extractionThe water layer was extracted with ethyl acetate (50 ml) three times
7. washthe combined organic layer was washed with water
8. dry with materialThe solution was dried over anhydrous magnesium sulfate
9. distillationThe solvent was distilled off under reduced pressure
10. customThe residue was purified by means of back-extraction