Terephthalaldehyde is an aromatic dialdehyde. Theoretically, the two aldehydes of terephthalaldehyde (TPA) are equivalent, so the single or double Schiff base from TPA and d-glucosamine (Glc) may be formed at the same time. It is used as an intermediate for the preparation of dyes and fluorescent whitening agents and in the synthesis of polyimines by reacting with aliphatic diamines. It is also used as a precursor for the preparation of paramagnetic microporous polymeric organic frameworks (POFs) through copolymerization with pyrrole, indole, and carbazole. As a good crosslinking agent, it could used in crosslinked chitosan hydrogel for the selective removal of anionic dyes[1].
WHITE TO LIGHT YELLOW CRYSTALLINE POWDER
Terephthalaldehyde (cas# 623-27-8) is a compound useful in organic synthesis.
Using p-xylene, carbon tetrachloride, azodiisobutyronitrile and chlorine as raw materials and solvents, chlorination to obtain benzyl chloride, and then oxidized under the catalytic effect of nitric acid and zinc nitrate, the addition of zinc nitrate improves the yield of terephthalaldehyde to more than 89%, and the purity of the product is higher than 99.0%. Chlorination hydrolysis usually uses highly toxic chlorine gas directly, which is very unfriendly to the environment. In order to avoid the direct use of chlorine gas, N-fluorobenzenesulfonamide and sodium chloride were firstly used to react with p-xylene to synthesize p-dichlorobenzene in a highly selective way, and then the crude product of terephthalaldehyde was obtained through the catalytic action of 98% concentrated sulfuric acid and manganese dioxide, and finally the oxidized masterbatch was neutralized by sodium hydroxide and the finished product of terephthalaldehyde was obtained by recrystallization from the mixture of ethanol and water with the yield of terephthalaldehyde of 77% by weight.
Terephthalaldehyde [623-27-8] M 134.1, m 116o, b 245 -248o/771mm. Crystallise terephthalaldehyde from water. [Beilstein 7 IV 2140.]
[1] Weng Q, et al. Controllable Synthesis and Biological Application of Schiff Bases from d-Glucosamine and Terephthalaldehyde. ACS Omega, 2020; 5: 24864–24870.
