Description
The substance 5-norbornene-2,3-dicarboxylic anhydride has a purity of approximately 99.5 % and
consists of two isomers, cis-5-norbrene-endo-2,3-dicarboxylic anhydride (99.2 %) and cis-5-norbreneexo-2,3-dicarboxylic anhydride (0.3 %). It has an estimated log Po/w = 2.3. Due to its chemical nature
as an anhydride it readily hydrolyses into the free diacid, norbornene-2,3-dicarboxylic acid. Therefore,
migration into aqueous foodstuffs will also lead to the presence of the two isomeric diacids. Melting
point of the substance is 163-165 °C.
Chemical Properties
white solid
Uses
5-Norbornene-2,3-dicarboxylic anhydride, as a copolymer monomer in polyester can coatings up to 18.3 % w/w in the final dry coating, does not pose a safety concern to the consumer under sterilised conditions and prolonged contact with all foodstuffs (except beverages).
Application
Nadic anhydride, also known as 5-Norbornene-2,3-dicarboxylic anhydride, is an organic anhydride derivative of norbornene. Besides its use as a component of polyester can coatings in foodstuffs, it is also used as an organic synthesis intermediate. 5-Norbornene-2,3-dicarboxylic anhydride (NA) can lower the cPC content of a polymerization reaction under zinc glutarate catalysis (3 MPa CO2, 60 °C, 0.8 wt% catalyst in neat PO) from 4.5% to about 1%, even if the anhydride concentration is as low as 0.3 mol%.
Reactions
Bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride reacts with methyl aminomethyllambertianate to give amide of bicyclo[2.2.1]heptan-1,2-dicarbocylic acid with a labdanoid substituent.
Safety Profile
Mild skin and severe eye irritant.When heated to decomposition it emits acrid smoke andirritating fumes.
Toxicity evaluation
In a cytogenetic test in vitro, 5-norbornene-2,3-dicarboxylic anhydride was clastogenic both in presence and absence of an exogenous metabolic activation system. Gene mutation assays in bacteria and cultured mammalian cells provided negative results. When administered to rats by the oral route at the maximum tolerated dose, 5-norbornene-2,3-dicarboxylic anhydride was not clastogenic/aneugenic in bone marrow, and did not induce DNA damage in liver and at the site of first contact (stomach) in a
combined micronucleus and comet assay. It is concluded that the clastogenic activity of 5-norbornene2,3-dicarboxylic anhydride observed in vitro is not expressed in vivo, and that 5-norbornene-2,3-
dicarboxylic anhydride does not raise concern for genotoxicity.
