Ethanol → 2-({2H,3H-thieno[3,4-b][1,4]dioxin-2-yl}methoxy)acetic acid

HRID 1825690Notes

Reaction equation

C([O:3][C:4](=[O:17])[CH2:5][O:6][CH2:7][CH:8]1[O:13][C:12]2=[CH:14][S:15][CH:16]=[C:11]2[O:10][CH2:9]1)C.C(O)C.[OH-].[K+]>O>[O:13]1[CH:8]([CH2:7][O:6][CH2:5][C:4]([OH:17])=[O:3])[CH2:9][O:10][C:11]2=[CH:16][S:15][CH:14]=[C:12]12

Participants

Conditions

Temperature: 35 °C

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, is 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 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.

Workup

customThe solvents were then removed by distillation
additionwere added
customSubsequently, the organic phase was separated
washwashed with a saturated solution of sodium chloride
dry with materialdried with anhydrous magnesium sulphate
concentrationconcentrated
customFinally the raw product was recrystallized from ethyl acetate/hexanes (1/1)
customresulting in pure (2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-ylmethoxy)-acetic acid

Sources & evidence

ORD record: ord-cffaa609a33f4021895ddb3726da27f2
Source dataset: uspto-grants-2006_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07048874B2

Reaction notes

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