反应详情

A mixture of ethyl 5-methoxyindole-2-carboxylate (8.15 g, 37.2 mmol), (prepared by the method described in Heterocycles Vol. 43, No. 2, p. 263-266), nitric acid adsorbed on silica gel (24 g) and dichloromethane (150 ml) was stirred at ambient temperature for 18 hours. The dichloromethane was removed in vacuo and the product washed off the silica with acetone. The acetone was evaporated in vacuo. The residue was treated again with nitric acid on silica (1 g) as above and the work up procedure repeated to give ethyl 5-hydroxy-4-nitroindole-2-carboxylate (5.8 g, 59%).

1. custom(prepared by the method
2. customThe dichloromethane was removed in vacuo
3. washthe product washed off the silica with acetone
4. customThe acetone was evaporated in vacuo
5. additionThe residue was treated again with nitric acid on silica (1 g) as above and the work up procedure