Acetic Anhydride → Ethyl 4-(acetyloxy)-2-ethyl-1-benzofuran-6-carboxylate

HRID 1643735Notes

Reaction equation

HRID 1643735 reaction equation
[CH2:1]([O:3][C:4]([CH:6]([CH:10]=[CH:11][C:12]1[O:13][C:14]([CH2:17][CH3:18])=[CH:15][CH:16]=1)C(O)=O)=O)[CH3:2].C([O-])(=[O:21])C.[Na+].[C:24]([O:27][C:28](=O)[CH3:29])(=[O:26])C>>[C:1]([O:3][C:4]1[C:16]2[CH:15]=[C:14]([CH2:17][CH3:18])[O:13][C:12]=2[CH:11]=[C:10]([C:24]([O:27][CH2:28][CH3:29])=[O:26])[CH:6]=1)(=[O:21])[CH3:2]

Participants

4

Reactant 3

HCID 7918Acetic AnhydrideHCID 517045Sodium AcetateHCID 66755689(Ethoxycarbonyl)-4-(5-ethyl-2-furyl)but-3-enoic acid

Product 1

HCID 59559992Ethyl 4-(acetyloxy)-2-ethyl-1-benzofuran-6-carboxylateYield 28%

Procedure

A mixture of (ethoxycarbonyl)-4-(5-ethyl-2-furyl)but-3-enoic acid (45.4 g, 0.18 mol) and sodium acetate (59.0, 0.72 mol) in acetic anhydride (450 mL) was heated to reflux for 5 hours. TLC (petroleum ether/EtOAc 4:1) indicated complete consumption of the starting material. The reaction mixture was concentrated and the residue was poured into 15% aq. Na2CO3 (500 mL), and extracted with EtOAc (500 mL×3). The combined organic layers was washed with brine (200 mL), dried over Na2SO4, and concentrated. The product was purified via silica gel column chromatography using petroleum ether/EtOAc (70:1) to afford the desired compound (13.0 g, 28%) as a yellow solid.

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 5 hours
  3. customconsumption of the starting material
  4. concentrationThe reaction mixture was concentrated
  5. additionthe residue was poured into 15% aq. Na2CO3 (500 mL)
  6. extractionextracted with EtOAc (500 mL×3)
  7. washThe combined organic layers was washed with brine (200 mL)
  8. dry with materialdried over Na2SO4
  9. concentrationconcentrated
  10. customThe product was purified via silica gel column chromatography

Sources & evidence

ORD record
ord-76072c6bcbdf4f2da68b04460cd3a9fd
Source dataset
uspto-grants-2012_02
Patent number
US08119624B2

Reaction notes

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