反应详情

温度

120 °C

Trifluoroacetic acid (2.19 g, 19.2 mmol) was added to a suspension of the product from step (iii) (10.0 g, 19.2 mmol) and n-pentylamine (5.0 g, 57.6 mmol) in butyl acetate (65.0 g), and the mixture was heated at 120° C. for 6 hours. The mixture was cooled and concentrated under reduced pressure to give a solid. A suspension of the solid in toluene (30.0 g) was concentrated under reduced pressure again to give a solid. 5% aq. LiOH (60.0 g) was added to the solution of the solid in toluene (55.0 g) and THF (14.0 g), and the mixture was stirred at 40° C. The separated organic layer was washed with water (60.0 g) at 40° C. and concentrated under reduced pressure to afford a solid. A suspension of the obtained solid in toluene (42.0 g) was stirred at 54° C. for 1 hour and cooled to 5° C. and stirred at 5° C. for 10 hours. The resulting precipitate was collected by filtration and washed with acetonitrile (5.0 g) and water (12.0 g) respectively to give the subtitle compound as wet crystals. 5.90 g. This product was used in the next step without desiccation.

1. temperatureThe mixture was cooled
2. concentrationconcentrated under reduced pressure
3. customto give a solid
4. concentrationwas concentrated under reduced pressure again
5. customto give a solid
6. washThe separated organic layer was washed with water (60.0 g) at 40° C.
7. concentrationconcentrated under reduced pressure
8. customto afford a solid
9. temperaturecooled to 5° C.
10. stirringstirred at 5° C. for 10 hours
11. filtrationThe resulting precipitate was collected by filtration
12. washwashed with acetonitrile (5.0 g) and water (12.0 g) respectively