反应详情

A 4N hydrochloric acid-ethyl acetate solution (120 ml) was cooled in an ice bath. After adding tert-butyl [4-(4-benzyloxycarbonylamino-3-fluorophenoxy)pyridin-2-yl]carbamate (3.92 g) thereto while stirring, the stirring was continued for 10 minutes in an ice bath. The reaction mixture was then stirred for 3.5 hours at room temperature. The reaction mixture was concentrated under reduced pressure. Ethyl acetate (150 ml) and saturated aqueous sodium hydrogencarbonate (70 ml) were added thereto for partition. The aqueous layer was extracted with ethyl acetate (50 ml). The combined organic layers were washed with brine and dried over anhydrous sodium sulfate. The dried organic layer was concentrated under reduced pressure. The obtained crystals were then suspended in a mixed solvent of hexane-ethyl acetate (5:1). The crystals were filtered off and washed with a mixed solvent of hexane-ethyl acetate (5:1). They were then dried by aspiration at room temperature to provide the title compound (2.93 g, 95.9%) as pale yellow crystals.

1. stirringThe reaction mixture was then stirred for 3.5 hours at room temperature
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. additionEthyl acetate (150 ml) and saturated aqueous sodium hydrogencarbonate (70 ml) were added
4. customfor partition
5. extractionThe aqueous layer was extracted with ethyl acetate (50 ml)
6. washThe combined organic layers were washed with brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationThe dried organic layer was concentrated under reduced pressure
9. filtrationThe crystals were filtered off
10. washwashed with a mixed solvent of hexane-ethyl acetate (5:1)
11. customThey were then dried by aspiration at room temperature