Acetic Anhydride → 4-formyl-3,8-dihydroxy-1,9-dimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepine-6-carboxylic acid methyl ester

HRID 1692622Notes

Reaction equation

HRID 1692622 reaction equation
[CH3:1][O:2][C:3](=[O:27])[C:4]1[CH:9]=[C:8]([OH:10])[C:7]([CH3:11])=[C:6](O)[C:5]=1[O:13][C:14]1[C:19]([CH:20]=[O:21])=[C:18]([OH:22])[CH:17]=[C:16]([CH3:23])[C:15]=1[C:24]([OH:26])=[O:25].C(OC(=O)C)(=O)C>>[CH3:1][O:2][C:3]([C:4]1[C:5]2[O:13][C:14]3[C:19]([CH:20]=[O:21])=[C:18]([OH:22])[CH:17]=[C:16]([CH3:23])[C:15]=3[C:24](=[O:25])[O:26][C:6]=2[C:7]([CH3:11])=[C:8]([OH:10])[CH:9]=1)=[O:27]

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 594023992-(3-Methyl-6-formyl-2-carboxy-5-hydroxy-phenoxy)-3,5-dihydroxy-4-methyl-benzoic acid methyl ester

Product 1

HCID 866432524-formyl-3,8-dihydroxy-1,9-dimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepine-6-carboxylic acid methyl esterYield 30%

Conditions

Temperature
145 °C

Procedure

Dry 2-(3-methyl-6-formyl-2-carboxy-5-hydroxy-phenoxy)-3,5-dihydroxy-4-methyl-benzoic acid methyl ester (1 mmol) was added to acetic anhydride (15 ml) and the resulting mixture was refluxed for five hours at 145° C. The excess acetic anhydride was distilled out. The residue was added with crushed ice and then extracted with ethyl acetate. The combined extracts were washed successively with saturated NH4Cl solution and water, dried over anhydrous Na2SO4, concentrated and purified by column chromatography to afford 4-formyl-3,8-dihydroxy-1,9-dimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepine-6-carboxylic acid methyl ester (30%).

Workup

  1. distillationThe excess acetic anhydride was distilled out
  2. additionThe residue was added with crushed ice
  3. extractionextracted with ethyl acetate
  4. washThe combined extracts were washed successively with saturated NH4Cl solution and water
  5. dry with materialdried over anhydrous Na2SO4
  6. concentrationconcentrated
  7. custompurified by column chromatography

Sources & evidence

ORD record
ord-c39daee744f041818dc34bb5516a9eae
Source dataset
uspto-grants-2012_04
Patent number
US08158623B2

Reaction notes

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