Reaktion #52032

Reaktionsgleichung

(2,3-Dihydro-thieno[3,4-b][1,4]dioxin-2-ylmethoxy)-acetic acid ethyl ester

ethanol

Potassium hydroxide

→

(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl-methoxy)-acetic acid

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvents were then removed by distillation, ethyl acetate (50 mL), ice-water (50 mL) and concentrated hydrochloric acid (5 mL)
2. 2
   workup.ADDITIONwere added
3. 3
   SonstigeSubsequently, the organic phase was separated
4. 4
   Waschenwashed with a saturated aqueous solution of sodium chloride
5. 5
   Trocknendried with anhydrous magnesium sulphate
6. 6
   Einengenconcentrated
7. 7
   SonstigeFinally the raw product was recrystallized from ethyl acetate/hexanes (1/1)
8. 8
   Sonstigeresulting in pure (2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-ylmethoxy)-acetic acid

Vorschrift

(2,3-Dihydro-thieno[3,4-b][1,4]dioxin-2-ylmethoxy)-acetic acid ethyl ester (10.2 g, 40 mmol) was dissolved into ethanol (100 mL) and water (50 mL), blanketed by nitrogen. Potassium hydroxide (2.9 g) was added and the mixture was heated at 35° C. for 30 min. The solvents were then removed by distillation, ethyl acetate (50 mL), ice-water (50 mL) and concentrated hydrochloric acid (5 mL) were added and the mixture was vigorously stirred. Subsequently, the organic phase was separated, washed with a saturated aqueous solution of sodium chloride, dried with anhydrous magnesium sulphate and concentrated. Finally the raw product was recrystallized from ethyl acetate/hexanes (1/1) resulting in pure (2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-ylmethoxy)-acetic acid as demonstrated by NMR and mass spectroscopy.

Quelle