反应详情

A solution of the obtained diethyl 2,6-difluoro-4-nitrophenylmalonate (42 g) in a mixed solvent of acetic acid (200 mL), water (150 mL) and conc. sulfuric acid (50 mL) was heated under reflux for 18 hr, and the reaction mixture was concentrated under reduced pressure. To the residue was added water, and the mixture was extracted with ethyl acetate (×2). The organic layer was back-extracted with 10% sodium carbonate aqueous solution, and the aqueous layer was acidified with 2N hydrochloric acid. The precipitate was collected by filtration to give 2-(2,6-difluoro-4-nitrophenyl)acetic acid (27.90 g, 128 mmol, 92.0%) as white crystals.

1. temperatureunder reflux for 18 hr
2. concentrationthe reaction mixture was concentrated under reduced pressure
3. additionTo the residue was added water
4. extractionthe mixture was extracted with ethyl acetate (×2)
5. extractionThe organic layer was back-extracted with 10% sodium carbonate aqueous solution
6. filtrationThe precipitate was collected by filtration