Sodium Hydroxide → 3,5-Dimethoxy-1-benzofuran-2-carboxylic acid

HRID 256345Notes

Reaction equation

HRID 256345 reaction equation
[CH3:1][O:2][C:3]1[C:7]2[CH:8]=[C:9]([O:12][CH3:13])[CH:10]=[CH:11][C:6]=2[O:5][C:4]=1[C:14]([O:16]C)=[O:15].[OH-].[Na+]>CO>[CH3:1][O:2][C:3]1[C:7]2[CH:8]=[C:9]([O:12][CH3:13])[CH:10]=[CH:11][C:6]=2[O:5][C:4]=1[C:14]([OH:16])=[O:15]

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 13682649HCID 13682649, compound

Product 1

HCID 136826533,5-Dimethoxy-1-benzofuran-2-carboxylic acidYield 96%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 10.6 g (0.045 mole) of 3,5-dimethoxy-2 -benzofurancarboxylic acid, methyl ester in 80 ml of methanol is treated with 75 ml of 1.0 N aqueous sodium hydroxide solution. The new mixture is stirred at reflux for 45 minutes, cooled, and added to 750 g of ice/water. After extraction with dichloromethane, 3×300 ml) the aqueous layer is cooled in ice and acidified with glacial acetic acid to precipitate the crude product. The precipitate is filtered and washed with water to yield 9.6 g (88% crude yield) of 3,5-dimethoxy-2-benzofurancarboxylic acid. A sample recrystallized from ethyl acetate is analytically pure, mp 168° C.-dec.

Workup

  1. temperatureat reflux for 45 minutes
  2. temperaturecooled
  3. extractionAfter extraction with dichloromethane, 3×300 ml) the aqueous layer
  4. temperatureis cooled in ice
  5. customto precipitate the crude product
  6. filtrationThe precipitate is filtered
  7. washwashed with water

Sources & evidence

ORD record
ord-ca4fddc7abee41a4801902f291214cbd
Source dataset
uspto-grants-1987_10
Patent number
US04703053

Reaction notes

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