反应详情

50 ml of 2N sodium hydroxide solution are added to a solution of 7.8 g (45 mmol) of 3-cyanomethylchroman in 150 ml of ethanol and the whole is boiled under reflux for 16 hours. After cooling, the reaction mixture is concentrated by evaporation in vacuo. The residue is dissolved in water and extracted with diethyl ether. The aqueous phase is acidified with hydrochloric acid (36% strength) and extracted by shaking with dichloromethane. The combined dichloromethane extracts are dried over sodium sulphate and concentrated by evaporation in vacuo. 8.3 g (96%) of 3-carboxymethylchroman are obtained in the form of colourless crystals which melt at 106°-107°.

1. temperatureunder reflux for 16 hours
2. temperatureAfter cooling
3. concentrationthe reaction mixture is concentrated by evaporation in vacuo
4. dissolutionThe residue is dissolved in water
5. extractionextracted with diethyl ether
6. extractionextracted
7. dry with materialThe combined dichloromethane extracts are dried over sodium sulphate
8. concentrationconcentrated by evaporation in vacuo