Reaction #52032

Reaction equation

(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

Solvents

water

Conditions

Workup

1. 1
   OtherThe 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
   OtherSubsequently, the organic phase was separated
4. 4
   Washwashed with a saturated aqueous solution of sodium chloride
5. 5
   Dryingdried with anhydrous magnesium sulphate
6. 6
   Concentrationconcentrated
7. 7
   OtherFinally the raw product was recrystallized from ethyl acetate/hexanes (1/1)
8. 8
   Otherresulting in pure (2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-ylmethoxy)-acetic acid

Procedure

(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.

Source