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

HRID 890327Notes

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, 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 an aqueous, saturated sodium chloride solution, 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, ethyl acetate (50 mL), ice-water (50 mL) and concentrated hydrochloric acid (5 mL)
additionwere added
customSubsequently, the organic phase was separated
washwashed with an aqueous, saturated sodium chloride solution
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-62f4ae6c24ec44d2bf256e2ad3b3354d
Source dataset: uspto-grants-2006_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06995223B2

Reaction notes

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