反应详情

A stirred suspension of isatin, also called 1H-indole-2,3-dione, available from Sigma-Aldrich, (3.80 g, 25 mmol) and malonic acid (8.06 g, 77 mmol) in acetic acid (150 ml) was refluxed for 16 h. Acetic acid was removed under reduced pressure, the residue was suspended in water (150 ml), filtered and washed with water (100 ml) to give a brown solid. The solid was stirred in NaHCO3 saturated aqueous solution (200 ml) and the insoluble material was filtered off. The filtrate was acidified to pH 1-2 with concentrated HCl and the precipitate was filtered, washed with water and dried to obtain the desired product as a grey solid (2.2 g, 11.6 mmol, Yield 40%).

1. customAcetic acid was removed under reduced pressure
2. filtrationfiltered
3. washwashed with water (100 ml)
4. customto give a brown solid
5. filtrationthe insoluble material was filtered off
6. filtrationthe precipitate was filtered
7. washwashed with water
8. customdried