Reaction #657349

Reaction equation

5-methoxyanthranilic acid

acetic anhydride

→

title compound

Yield 77.0%

2-methyl-6-(methyloxy)-4H-3,1-benzoxazin-4-one

Yield 77.0%

Conditions

Workup

1. 1
   Temperaturebefore being cooled
2. 2
   Concentrationconcentrated under reduced pressure
3. 3
   ConcentrationThe crude residue was then concentrated twice in the presence of toluene
4. 4
   Filtrationbefore being filtered
5. 5
   Washwashed with ether

Procedure

A solution of 5-methoxyanthranilic acid (7.8 g, 46.5 mmol) was refluxed in acetic anhydride (60 mL) for 2 h15 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.

Source