反应详情

A 4 N hydrogen chloride-methanol solution (80 mL) of 5-hydroxyindole-2-carboxylic acid (3.0 g) was heated overnight under reflux. The solvent was evaporated off from the reaction liquid under reduced pressure, aqueous saturated sodium hydrogencarbonate solution was added to the resulting residue, and extracted with ethyl acetate. The organic layer was dried with anhydrous magnesium sulfate, and the solvent was evaporated off under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane/ethyl acetate=4/1 to 3/2) to obtain methyl 5-hydroxy-1H-indole-2-carboxylate (2.3 g) as a pale brown solid.

1. temperatureunder reflux
2. customThe solvent was evaporated off from the reaction liquid under reduced pressure, aqueous saturated sodium hydrogencarbonate solution
3. additionwas added to the resulting residue
4. extractionextracted with ethyl acetate
5. dry with materialThe organic layer was dried with anhydrous magnesium sulfate
6. customthe solvent was evaporated off under reduced pressure
7. customThe resulting residue was purified through silica gel column chromatography (hexane/ethyl acetate=4/1 to 3/2)