Ethanol → 2-(3,4-dihydro-2H-1-benzopyran-3-yl)acetic acid

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Reaction Steps

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°.

Provenance & Evidence