Isatoic anhydride
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| Names | |
|---|---|
| Preferred IUPAC name
2H-3,1-Benzoxazine-2,4(1H)-dione | |
| Identifiers | |
| ECHA InfoCard | 100.003.869 |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| 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).
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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
[edit]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.
Uses
[edit]Isatoic anhydride has been used as a precursor for the synthesis of methaqualone[3] and related 4-quinazolinone-based pharmaceutical drugs, including:
- Tioperidone
- Tranilast
- Pelanserin
- Diproqualone
- Antrafenine
- SJ-733
- Nicafenine
- Molinazone
- Cloperidone
- SGB 1534
References
[edit]- ^ 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.
- ^ Etienne F. van Zyl (2001). "A survey of reported syntheses of methaqualone and some positional and structural isomers". Forensic Sci. Int. 122 (2–3): 142–149. doi:10.1016/S0379-0738(01)00484-4. PMID 11672968.