Pyridine → Acetanthranil

Participants

Reaction Conditions

Reaction Steps

The isatoic anhydride and pyridine were combined in a round bottomed, 3-necked flask equipped with a mechanical stirrer, thermometer, reflux condenser, dropping funnel and drying tube. The isatoic anhydride suspension was heated to 45° C and the acetic anhydride was added over a period of 30 minutes. Carbon dioxide evolution occurred during the addition of the acetic anhydride. The reaction mixture was heated to 90° C for 1.5 hours. The evolution of carbon dioxide stopped. The reaction mixture was concentrated under reduced pressure (15 mm. of Hg). The residue was crystallized from 100 ml of cyclohexane to give 42 parts by weight (86% yield) of 2-methyl-4H-3,1-benzoxazine-4-one with m.p. 79°-81° C.

Provenance & Evidence