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

HRID 2041788Notes

Reaction equation

HRID 2041788 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 71%

Procedure

A solution of 5-methoxyanthranilic acid (Lancaster) (41.8 g, 0.25 mol) was refluxed in acetic anhydride (230 mL) for 3.5 h before being concentrated under reduced pressure. The crude compound was then concentrated twice in the presence of toluene before being filtered and washed twice with ether to yield to the title compound (33.7 g, 71% yield) as a brown solid; LC/MS (Method D): m/z 192 [M+H]+, Rt 1.69 min.

Workup

  1. concentrationbefore being concentrated under reduced pressure
  2. concentrationThe crude compound was then concentrated twice in the presence of toluene
  3. filtrationbefore being filtered
  4. washwashed twice with ether

Sources & evidence

ORD record
ord-09cb0554a596449bbbdf4a70ade06326
Source dataset
uspto-grants-2013_11
Patent number
US08580957B2

Reaction notes

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