Acetic Acid → Methyl 6-hydroxy-2,3-dihydrobenzofuran-4-carboxylate

HRID 1643549Notes

Reaction equation

HRID 1643549 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:6]=[C:7]([OH:14])[CH:8]=[C:9]2[O:13][CH:12]=[CH:11][C:10]=12)=[O:4].C(O)(=O)C>CCOC(C)=O.[Pd]>[CH3:1][O:2][C:3]([C:5]1[CH:6]=[C:7]([OH:14])[CH:8]=[C:9]2[O:13][CH2:12][CH2:11][C:10]=12)=[O:4]

Participants

5

Reactant 2

HCID 176Acetic AcidHCID 595601586-Hydroxy-benzofuran-4-carboxylic acid methyl ester

Product 1

HCID 59559984Methyl 6-hydroxy-2,3-dihydrobenzofuran-4-carboxylate

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 6-hydroxy-benzofuran-4-carboxylic acid methyl ester (6d) (354 mg, 1.82 mmol) in EtOAc was added acetic acid (1 mL) and Pd on carbon (40 mg). The reaction mixture was stirred under hydrogen gas balloon overnight. The mixture was filtered through Celite and concentrated to give a pale yellow solid which was used without further purification. LCMS and NMR showed it was a mixture of 6-hydroxy-benzofuran-4-carboxylic acid methyl ester and 6-hydroxy-2,3-dihydro-benzofuran-4-carboxylic acid methyl ester (2:1). 1H NMR (400 MHz, CDCl3) δ 7.02 (d, J=2.27 Hz, 2 H) 6.53 (d, J=2.27 Hz, 1 H) 4.61 (t, J=8.72 Hz, 2 H) 3.90 (s, 3 H) 3.44 (t, J=8.72 Hz, 2 H).

Workup

  1. filtrationThe mixture was filtered through Celite
  2. concentrationconcentrated
  3. customto give a pale yellow solid which
  4. customwas used without further purification
  5. additiona mixture of 6-hydroxy-benzofuran-4-carboxylic acid methyl ester and 6-hydroxy-2,3-dihydro-benzofuran-4-carboxylic acid methyl ester (2:1)

Sources & evidence

ORD record
ord-c84db56c0ac4421d91111873f75cd3a6
Source dataset
uspto-grants-2012_02
Patent number
US08119624B2

Reaction notes

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