Acetic Anhydride → 6-methoxy-2-methyl-4H-benzo[d][1,3]oxazin-4-one

HRID 513163Notes

Reaction equation

HRID 513163 reaction equation
[CH3:1][O:2][C:3]1[CH:11]=[C:7]([C:8]([OH:10])=[O:9])[C:6]([NH2:12])=[CH:5][CH:4]=1.[C:13](OC(=O)C)(=O)[CH3:14]>>[CH3:13][C:14]1[O:9][C:8](=[O:10])[C:7]2[CH:11]=[C:3]([O:2][CH3:1])[CH:4]=[CH:5][C:6]=2[N:12]=1

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 2779305-Methoxyanthranilic acid

Product 1

HCID 6055556-methoxy-2-methyl-4H-benzo[d][1,3]oxazin-4-oneYield 77%

Procedure

A solution of 5-methoxyanthranilic acid (7.8 g, 46.5 mmol) was refluxed in acetic anhydride (60 mL) for 2 h 15 before being cooled and concentrated under reduced pressure. The crude residue was then concentrated twice in the presence of toluene before being filtered and washed with ether to yield to the title compound (6.8 g, 77% yield) as a beige solid; LC/MS: m/z 192 [M+H]+, Rt 1.69 min.

Workup

  1. temperaturebefore being cooled
  2. concentrationconcentrated under reduced pressure
  3. concentrationThe crude residue was then concentrated twice in the presence of toluene
  4. filtrationbefore being filtered
  5. washwashed with ether

Sources & evidence

ORD record
ord-12c030b893c54d289dc8e4b63a2802f5
Source dataset
uspto-grants-2015_08
Patent number
US09102677B2

Reaction notes

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