isatoic anhydride
{{Chembox
| ImageFile = Isatoic anhydride.PNG
| ImageSize = 122 px
| ImageAlt =
| PIN = 2H-3,1-Benzoxazine-2,4(1H)-dione
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 118-48-9
| ChEMBL = 346059
| ChemSpiderID = 8056
| DrugBank = DB11593
| EC_number = 204-255-0
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = R8TFA74Y4U
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 8359
| StdInChI=1S/C8H5NO3/c10-7-5-3-1-2-4-6(5)9-8(11)12-7/h1-4H,(H,9,11)
| StdInChIKey = TXJUTRJFNRYTHH-UHFFFAOYSA-N
| SMILES = C1=CC=C2C(=C1)C(=O)OC(=O)N2
}}
|Section2={{Chembox Properties
| C=8|O=3|H=5|N=1
| MolarMass =
| Appearance = white solid
| Density =
| MeltingPtC = 243
| BoilingPt =
| Solubility = }}
|Section3={{Chembox Hazards
| GHS_ref=[https://pubchem.ncbi.nlm.nih.gov/compound/8359#section=Safety-and-Hazards]
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|317|319}}
| PPhrases = {{P-phrases|261|264+265|272|280|302+352|305+351+338|321|333+317|337+317|362+364|501}}
| MainHazards =
| FlashPt =
| AutoignitionPt = }}
}}
Isatoic anhydride is an organic compound derived from anthranilic acid. A white solid, it is prepared by reaction of anthranilic acid with phosgene.{{cite journal|journal=Org. Synth.|year=1947|volume=27|page=45|doi=10.15227/orgsyn.027.0045|title=Isatoic anhydride|author=E. C. Wagner |author2=Marion F. Fegley. }}
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.{{cite journal|title=The Chemistry of Isatoic Anhydride|author=Coppola, Gary M.|journal=Synthesis|year=1980|volume=7|issue=7 |pages=505–36|doi=10.1055/s-1980-29110}} 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{{cite journal | title = A survey of reported syntheses of methaqualone and some positional and structural isomers | author = Etienne F. van Zyl | journal = Forensic Sci. Int. | volume = 122 | pages = 142–149 | date = 2001 | issue = 2–3 | doi = 10.1016/S0379-0738(01)00484-4 | pmid = 11672968 }} and related 4-quinazolinone-based pharmaceutical drugs, including: