反应详情

5-Methoxy-1H-indole-2-carboxylic acid (10 g, 52.3 mmol) in EtOH (400 ml) containing 36% H2SO4 (7 ml) was heated under reflux for 18 hr. After cooling the mixture was neutralised with 2N NaOH (to pH 7) and extracted with EtOAc (3×150ml), the combined extracts were washed with 10% NaHCO3 (2×25 ml), dried (MgSO4), filtered and evaporated to afford 5-methoxy-1H-indole-2-carboxylic acid ethyl ester as a brown solid (9.52 g, 43.3 mmol, 82%) Mp. 154-155° C., MS: m/e=219.1 (M+).

1. temperaturewas heated
2. temperatureunder reflux for 18 hr
3. temperatureAfter cooling the mixture
4. extractionextracted with EtOAc (3×150ml)
5. washthe combined extracts were washed with 10% NaHCO3 (2×25 ml)
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. customevaporated