反应详情

0.144 ml (2.70 mmol) of concentrated sulfuric acid is added, at ambient temperature, to a solution of 5.98 g (33.75 mmol) of 6-hydroxy-1H-indole-2-carboxylic acid in 350 ml of methanol. The mixture is refluxed for 9 days and the reaction mixture is then concentrated to dryness under reduced pressure. The residue obtained is taken up in water and alkalinized to pH9 with a 38% potassium hydroxide solution, and the product is then extracted 6 times with ethyl acetate. The organic phases are combined and then dried over anhydrous magnesium sulfate, filtered, and concentrated to dryness under reduced pressure, to give 5.81 g of methyl 6-hydroxy-1H-indole-2-carboxylate in the form of a brown solid.

1. temperatureThe mixture is refluxed for 9 days
2. concentrationthe reaction mixture is then concentrated to dryness under reduced pressure
3. customThe residue obtained
4. extractionthe product is then extracted 6 times with ethyl acetate
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated to dryness under reduced pressure