反应详情

To a suspension of 3-(4-cyano-2-nitro-phenyl)-2-oxo-propionic acid ethyl ester (1.21 g, 4.62 mmol) in acetic acid (50 mL) and water (8 mL) add zinc powder (1.81 g, 27.7 mmol) portionwise over 2 h. Stir at rt for 3 h then filter to remove the solids. Concentrate the filtrate to a volume of 10 mL, dilute with EtOAc (40 mL), and filter again to remove insoluble material. Concentrate the filtrate to give the desired product 6-cyano-1H-indole-2-carboxylic acid ethyl ester as a solid (670 mg, 3.13 mmol).

1. filtrationthen filter
2. customto remove the solids
3. concentrationConcentrate the filtrate to a volume of 10 mL
4. additiondilute with EtOAc (40 mL)
5. filtrationfilter again
6. customto remove insoluble material
7. concentrationConcentrate the filtrate