Isatoic anhydride is an organic compound derived from anthranilic acid.

Alcoholysis proceeds similarly, affording the ester: Amines also effect ring-opening.

Active methylene compounds and carbanions replace oxygen giving hydroxyquinolinone derivatives.

[2] Isatoic anhydride is used as a blowing agent in the polymer industry, an application that exploits its tendency to release CO2.

Isatoic anhydride has been used as a precursor for the synthesis of methaqualone[3] and related 4-quinazolinone-based pharmaceutical drugs, including: