反应详情

A 2N-hydrochloric acid (5 mL) solution of the compound (480 mg) obtained in Example 45 was stirred at 80° C. for 3 hours. After the reaction solution was cooled to room temperature, the pH was adjusted to 12 with an aqueous 2N-sodium hydroxide solution. The aqueous layer was extracted four times with dichloromethane. The combined organic layer was washed with saturated brine and then dried over anhydrous magnesium sulfate. After removing the anhydrous magnesium sulfate by filtration, the filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography (ethyl acetate:10%-saturated aqueous ammonia-methanol=1:0→7:3) to obtain the title compound (277 mg) having the following physical properties.

1. extractionThe aqueous layer was extracted four times with dichloromethane
2. washThe combined organic layer was washed with saturated brine
3. dry with materialdried over anhydrous magnesium sulfate
4. customAfter removing the anhydrous magnesium sulfate
5. filtrationby filtration
6. concentrationthe filtrate was concentrated under reduced pressure
7. customThe residue was purified by silica gel chromatography (ethyl acetate:10%-saturated aqueous ammonia-methanol=1:0→7:3)