反应详情

To a solution of 20 g (137 mmol) 1H-indazole-5-carbaldehyde in acetonitrile (580 ml), 28 g (157 mmol) 1-bromopyrrolidine-2,5-dione were added over 20 min at room temperature. The resulting suspension was stirred under reflux for 30 min, then cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in ethyl acetate (1500 ml), and the solution was washed with water and with brine, dried over sodium sulfate, filtered and concentrated under reduced pressure. The crude product was triturated with ethyl acetate. After filtration, the precipitate was dried under vacuum to yield the title compound as a white solid (30.9 g, 75% of th.).

1. temperatureunder reflux for 30 min
2. concentrationconcentrated under reduced pressure
3. dissolutionThe residue was dissolved in ethyl acetate (1500 ml)
4. washthe solution was washed with water and with brine
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe crude product was triturated with ethyl acetate
9. filtrationAfter filtration
10. customthe precipitate was dried under vacuum