Acetic Anhydride → 4-Methoxy-1,3-dihydro-2-benzofuran-1,3-dione

HRID 424114

Reaction equation

HRID 424114 reaction equation
C(OC(=O)C)(=O)C.[CH3:8][O:9][C:10]1[CH:18]=[CH:17][CH:16]=[C:12]([C:13]([OH:15])=O)[C:11]=1[C:19]([OH:21])=[O:20]>O1CCCC1>[CH3:8][O:9][C:10]1[CH:18]=[CH:17][CH:16]=[C:12]2[C:13]([O:21][C:19](=[O:20])[C:11]=12)=[O:15]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 3152183-Methoxyphthalic acid

Product 1

HCID 2911934-Methoxy-1,3-dihydro-2-benzofuran-1,3-dioneYield 99.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Acetic anhydride (70 ml) was added to a mixture of 3-methoxyphthalic acid (51.0 g, 0.26 mol) in anhydrous tetrahydrofuran (250 ml) and the mixture was stirred and held at reflux for 4 hours. Upon cooling to room temperature the solvent was removed in vacuo and the resulting solid material was dried in a vacuum oven at 50° C. overnight to afford 3-methoxyphthalic anhydride (45.9 g, 99%) as a colourless solid. 1H NMR (DMSO-d6) 7.97 (1H, dd), 7.63 (1H, d), 7.60 (1H, d), 4.02 (3H, s). MS: [M+H]+ 179.

Workup

  1. temperatureat reflux for 4 hours
  2. customwas removed in vacuo
  3. customthe resulting solid material was dried in a vacuum oven at 50° C. overnight

Sources & evidence

ORD record
ord-9395b52f44e0434d8de65dec1c770de9
Source dataset
uspto-grants-2012_01
Patent number
US08101648B2

Linked notes

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