反应详情

Methyl 7-amino-2,3-dihydrobenzofuran-4-carboxylate 1g (2.30 g, 11.90 mmol) was dissolved in 80 mL of the mixture solvent of methanol and tetrahydrofuran (V/V=1:1) followed by the addition of a 1 M solution of lithium hydroxide solution (47.6 mL, 47.60 mmol) in tetrahydrofuran. The reaction solution was heated to reflux for 5 hours, then cooled down to room temperature, stirred for 12 hours. The reaction solution was added with 20 mL of water and concentrated under reduced pressure. The resulting residue was added with 100 mL of water, extracted with ethyl acetate (50 mL×2), the combined aqueous phase was added dropwise with 1 M hydrochloric acid to adjust pH to 3 resulting in the formation of precipitate. The precipitate was filtered to obtain the title compound 7-amino-2,3-dihydrobenzofuran-4-carboxylic acid 22e (1.70 g, yield: 80.0%) as a gary solid.

1. temperatureThe reaction solution was heated
2. temperatureto reflux for 5 hours
3. concentrationconcentrated under reduced pressure
4. additionThe resulting residue was added with 100 mL of water
5. extractionextracted with ethyl acetate (50 mL×2)
6. additionthe combined aqueous phase was added dropwise with 1 M hydrochloric acid
7. filtrationThe precipitate was filtered