反应详情

To a solution of the above-mentioned crude product of a mixture of tert-butyl(2-fluoro-5-nitrophenyl)carbamate and di-tert-butyl(2-fluoro-5-nitrophenyl)imidodicarbonate in ethanol (600 mL)/tetrahydrofuran (60 mL) was added 10% palladium-carbon (12.0 g), and the mixture was stirred at room temperature under a hydrogen atmosphere (1 atm) for 24 hr. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. To a solution of the obtained residue in methanol (200 mL)/tetrahydrofuran (50 mL) was added potassium carbonate (25.4 g, 184 mmol), and the mixture was stirred at 60° C. for 4 hr. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. To the obtained residue was added water (200 mL), and the mixture was extracted with ethyl acetate (300 mL, 100 mL). The combined organic layer was washed with saturated brine (100 mL), and dried over anhydrous sodium sulfate. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. The obtained residue was recrystallized from ethyl acetate and hexane to give the title compound (26.4 g, 63%) as pale-brown crystals.

1. filtrationThe insoluble material was filtered off
2. concentrationthe filtrate was concentrated under reduced pressure
3. stirringthe mixture was stirred at 60° C. for 4 hr
4. filtrationThe insoluble material was filtered off
5. concentrationthe filtrate was concentrated under reduced pressure
6. additionTo the obtained residue was added water (200 mL)
7. extractionthe mixture was extracted with ethyl acetate (300 mL, 100 mL)
8. washThe combined organic layer was washed with saturated brine (100 mL)
9. dry with materialdried over anhydrous sodium sulfate
10. filtrationThe insoluble material was filtered off
11. concentrationthe filtrate was concentrated under reduced pressure
12. customThe obtained residue was recrystallized from ethyl acetate and hexane