Reaktion #65439

Reaktionsgleichung

sodium hydroxide

ethyl 7-acetoxy-2,3-dihydro-1,4-benzodioxin-2-carboxylate

→

7-Hydroxy-2,3-dihydro-1,4-benzodioxin-2-carboxylic acid

Ausbeute 85.0%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenafter concentrating under reduced pressure
2. 2
   ExtraktionExtract with diethyl ether the acid which
3. 3
   Sonstigeprecipitates
4. 4
   Sonstigeafter drying
5. 5
   Einengenconcentration to dryness
6. 6
   Waschenwash the resulting acid with methylene chloride

Vorschrift

Under a nitrogen atmosphere, slowly add 75 mmol of a 10% aqueous sodium hydroxide solution to a solution of 2 g (7.5 mmol) of ethyl 7-acetoxy-2,3-dihydro-1,4-benzodioxin-2-carboxylate in 20 cm3 of methanol. Stir at room temperature for 6 hours and then, after concentrating under reduced pressure, acidify the mixture with a 2N hydrochloric acid solution. Extract with diethyl ether the acid which precipitates, then, after drying and concentration to dryness, wash the resulting acid with methylene chloride. 7-Hydroxy-2,3-dihydro-1,4-benzodioxin-2-carboxylic acid is thereby obtained in a yield of 85%.

Quelle