Isatoic anhydride

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Isatoic anhydride
Names
Preferred IUPAC name
2H-3,1-Benzoxazine-2,4(1H)-dione
Identifiers
ECHA InfoCard
100.003.869 Edit this at Wikidata
UNII
Properties
C8H5NO3
Molar mass 163.132 g·mol−1
Appearance white solid
Melting point 243 °C (469 °F; 516 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Isatoic anhydride is an organic compound derived from anthranilic acid. A white solid, it is prepared by reaction of anthranilic acid with phosgene.[1]

Reactions

Hydrolysis gives carbon dioxide and anthranilic acid. Alcoholysis proceeds similarly, affording the ester:

C6H4C2O3NH + ROH → C6H4(CO2R)(NH2) + CO2

Amines also effect ring-opening. Active methylene compounds and carbanions replace oxygen giving hydroxy

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

Uses

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

References

  1. .
  2. .
  3. ^ Etienne F. van Zyl (2001). "A survey of reported syntheses of methaqualone and some positional and structural isomers". Forens. Sci. Int. 122: 142–149.