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

HRID 1196009Notes

Reaction equation

HRID 1196009 reaction equation
[OH-:1].[Na+].C(C[CH:6]1[CH2:15][C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[O:8][CH2:7]1)#N.[CH2:16]([OH:18])[CH3:17]>>[C:16]([CH2:17][CH:6]1[CH2:15][C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[O:8][CH2:7]1)([OH:1])=[O:18]

Participants

4

Reactant 3

HCID 702EthanolHCID 14798Sodium HydroxideHCID 14838407Chroman-3-yl-acetonitrile

Product 1

HCID 148384122-(3,4-dihydro-2H-1-benzopyran-3-yl)acetic acidYield 96%

Procedure

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°.

Workup

  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

Sources & evidence

ORD record
ord-f309f832a3b74f39a5c5fed0b7879420
Source dataset
uspto-grants-1992_05
Patent number
US05112855

Reaction notes

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