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

HRID 570168Notes

Reaction equation

HRID 570168 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 A): 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-82427428e7e8415e90ce69b8cfd97d2c
Source dataset
uspto-grants-2015_05
Patent number
US09023842B2

Reaction notes

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