Isatoic anhydride
Isatoic anhydride is an organic compound derived from anthranilic acid. A white solid, it is prepared by reaction of anthranilic acid with phosgene.[1]
Names | |
---|---|
Preferred IUPAC name
2H-3,1-Benzoxazine-2,4(1H)-dione | |
Identifiers | |
ECHA InfoCard | 100.003.869 |
PubChem CID |
|
UNII | |
CompTox Dashboard (EPA) |
|
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).
Infobox references |
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 hydroxyquinolinone derivatives. Deprotonation followed by alkylation gives the N-substituted derivatives. Sodium azide gives the 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.
Isatoic anhydride has also been reported to be used as a precursor for the synthesis of methaqualone and related 4-quinazolinone based pharmaceutical drugs.[3]
References
- E. C. Wagner; Marion F. Fegley. (1947). "Isatoic anhydride". Org. Synth. 27: 45. doi:10.15227/orgsyn.027.0045.
- Coppola, Gary M. (1980). "The Chemistry of Isatoic Anhydride". Synthesis. 7 (7): 505–36. doi:10.1055/s-1980-29110.
- A survey of reported syntheses of methaqualone and some positional and structural isomers Etienne F. van Zyl Forens. Sci. Int. 122, 142-149 (2001)