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

HRID 1177076Notes

Reaction equation

HRID 1177076 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-a85bd5a792a84fa186f863e077f2c75c
Source dataset
uspto-grants-2010_11
Patent number
US07842713B2

Reaction notes

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