Synthesis of isatoic anhydride derivatives (microreview)

Isatoic anhydride (1H-benzo[d][1,3] oxazine-2,4-dione) and its derivatives are convenient building blocks for the synthesis of various nitrogen-containing heterocyclic structures, such as quinazolines, quinazolones, quinazolinediones, benzodiazepines, quinolinones, and tryptanthrin derivatives. (1) The following methods have been applied to the construction of benzo[d]-[ 1,3] oxazine-2,4-dione ring: cyclization of anthranilic acids, catalytic carbonylation of substituted anilines, transformation of phthalic anhydride derivatives, oxidation of isatin derivatives, and oxidation of indoles with Oxone. This microreview covers data from the last 10 years regarding the synthesis of 1H-benzo[d][1,3] oxazine-2,4-dione derivatives without considering the preparation of its heteroaromatic analogs.