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HONGKUN / PRODUCT DIRECTORY

Isatoic anhydride | CAS 118-48-9

A benzene-fused cyclic reagent that transfers an anthraniloyl unit through ring opening, supporting anthranilamide synthesis and published routes to dihydroquinazolinone heterocycles.

CAS118-48-9
Molecular formulaC8H5NO3
Molecular weight163.13 g/mol

Product overview

Ring-opening chemistry is the main reason to select isatoic anhydride. Its cyclic N-carboxyanhydride framework packages the ortho-amino aromatic acid motif in an electrophilic form, allowing amines to form anthranilamide derivatives with release of carbon dioxide. The benzene-fused ring contains two distinct carbonyl groups and an NH group; it is not interchangeable with isatin or phthalic anhydride. For purchasing, the intact cyclic structure matters as much as the nominal formula C8H5NO3. Qualification should consider anthranilic acid and other related material that may behave differently in the intended ring-opening sequence. Agree the assay method and sample preparation, particularly where titration is used alongside chromatographic identity or impurity data.

Chemical identity

Chemical name
Isatoic anhydride
CAS number
118-48-9
Molecular formula
C8H5NO3
Molecular weight
163.13 g/mol

Application context

Isatoic anhydride is used to introduce anthranilamide structures through reaction with amines. The resulting ortho-amino benzamide framework can then participate in further heterocycle construction. Published multicomponent research combines isatoic anhydride, an amine and an aldehyde to access dihydroquinazolinones; ring opening to an anthranilamide is part of the reported chemistry. The useful procurement distinction is between the cyclic starting reagent and the open-chain intermediates made from it. A material intended for this chemistry should be assessed for its ability to deliver the specified anthraniloyl component, with related-substance limits matched to the downstream route.

Chemistry and synthetic role

The ring incorporates a carbamate-like carbonyl and an aromatic acyl carbonyl. Nucleophilic opening followed by carbon dioxide loss provides an anthranilic acid derivative.

Quality review

Confirm the closed-ring identity

Use structure-sensitive identification to distinguish isatoic anhydride from anthranilic acid, isatin and other named aromatic carbonyl compounds.

Review ring-opened impurities

Ask how anthranilic acid and relevant by-products are resolved and quantified.

Check assay preparation and water

Agree a method that measures the intended reagent consistently; review water where the selected process requires it.

Preparing a specification

State isatoic anhydride, CAS 118-48-9, the required identity test and assay method, limits for anthranilic acid or route-relevant related substances, and the agreed water basis.

Packaging and storage

Packaging, closure and net weight are agreed for the selected grade, order quantity and destination. Confirm storage and transport requirements against the actual supplier SDS.

Documentation

Request a batch COA, specification, identity data and SDS. Confirm the availability of the analytical methods and any application-specific impurity results with the proposed supplier.

Procurement questions

Is isatoic anhydride the same as isatin?

No. They have different ring connectivity, oxygen content and reactivity.

Why is carbon dioxide mentioned in its chemistry?

Amine ring opening can release carbon dioxide while forming an anthranilamide derivative.

Does an acidimetric result fully establish suitability?

It should be considered with structural identification and a relevant impurity profile.

Technical sources
  1. Isatoic anhydride 804784Merck
  2. Isatoic anhydride I: Reactions with aminesACS / EPA HERO
  3. Amberlite-15 promoted synthesis of dihydroquinazolinonesRoyal Society of Chemistry