Synthese And Characterization Of New Triptycene-anhydride Derivatives

For the past twenty years, because of the unique rigid and three-dimensionalstructures, aromatic properties and highly active spot of the benzene ring, triptyceneand its derivatives have been found to have wide potential applications in materialchemistry, molecular machines, supramolecular chemistry, organic reaction andbiological medicine. Triptycene chemistry has become a new research area ofinterdiscipline. Aromatic polyimides are a kind of high performance polymers withwide applications, there are many researches show that polymers’ properties could beimproved by bring triptycene unit into the backbone. In order to improve polyimides’properties, we are devoted to researching on the synthese of new triptycene-anhydridederivatives. In this paper, based on the triptycene unit, we designed and synthesizedtriptycene dianhydride and triptycene trianhydride through principle of moleculedesign and synthese chemistry, by Diels-Alder cycloaddition reaction. The majorwork and conclusions are as follows:1.3,4-dimethyl aniline was mixed with chloral hydrate and hydroxylaminehydrochloride in one-pot to give3,4-dimethyl-isonitrosoacetanilide in high yield.Then we obtained5,6-dimethyl isatin by catalysis of concentrated sulfuric acid.Finaly,5,6-dimethyl isatin was oxidized by H2O2to afford2-amino-4,5-dimethyl-benzoic acid. The structure of the compound was characterized by FT-IR and1H NMR.2. In mixed solvent of Bis(2-methoxy ethyl)ether and1,2-Dichloroethane,2,3,6,7,12,13-hexamethyltriptycene was given by Diels-Alder cycloaddition reactionfrom2,3,6,7-Tetramethyl anthracene and2-amino-4,5-dimethylbenzoic acid.Subsequent oxidation of the methyl groups with KMnO4in pyridine providedtriptycene-2,3,6,7,12,13-hexacarboxylic acid, which was dehydrated in aceticanhydride to give triptycene-2,3,6,7,12,13-hexacarboxylic trianhydride. The structure of these compounds were characterized by FT-IR and1H NMR.3. We obtained2,3-dimethyl anthraquinone from phthalic anhydride ando-xylene by consecutive twice Friedel-Crafts acylation. Subsequent reduction of itwith zinc powder to give2,3-dimethyl anthracene. Also, we got2,3,6,7-tetramethyl-triptycene by Diels-Alder cycloaddition reaction from2,3-dimethyl anthracene and2-amino-4,5-dimethylbenzoic acid. Then,2,3,6,7-tetramethyltriptycene wasoxidized by KMnO4in pyridine to provide triptycene-2,3,6,7-tetracarboxylic acid.Finaly, triptycene-2,3,6,7-tetracarboxylic dianhydride was generated by dehydrationin acetic anhydride. The structure of these compounds were characterized by FT-IRand1H NMR.