Isatoic anhydride

Isatoic anhydride
Names
	Preferred IUPAC name 2H-3,1-Benzoxazine-2,4(1H)-dione
Identifiers
CAS Number	118-48-9 ;
ECHA InfoCard	100.003.869
PubChem CID	8359;
UNII	R8TFA74Y4U ;
CompTox Dashboard (EPA)	DTXSID6026955 ;
Properties
Chemical formula	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

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 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.CS1 maint: uses authors parameter (link)
^ Coppola, Gary M. (1980). "The Chemistry of Isatoic Anhydride". Synthesis. 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)

[1] E. C. Wagner, Marion F. Fegley. (1947). "Isatoic anhydride". Org. Synth. 27: 45. doi:10.15227/orgsyn.027.0045.CS1 maint: uses authors parameter (link)

[2] Coppola, Gary M. (1980). "The Chemistry of Isatoic Anhydride". Synthesis. 7: 505–36. doi:10.1055/s-1980-29110.

[3] A survey of reported syntheses of methaqualone and some positional and structural isomers Etienne F. van Zyl Forens. Sci. Int. 122, 142-149 (2001)

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