A kind of preparation method of 2,5-furandicarboxylic acid under mild conditions

Abstract

The invention discloses a preparation method of 2,5-furandicarboxylic acid under mild conditions. The preparation method comprises: making a mixed reaction system comprising 5-hydroxymethylfurfural and / or 5-hydroxymethylfurfural derivatives, hydrogen peroxide, catalyst, hydrogen peroxide stabilizer, alkali and water at 0-80 ℃ for 1-24 hours to prepare 2,5-furandicarboxylic acid, and the pH value of the mixed reaction system is 7-13. The method provided by the invention is carried out in an aqueous phase, using a non-noble metal catalyst, hydrogen peroxide as an oxygen source, and adjusting the pH value and adding a hydrogen peroxide stabilizer to prepare 2,5-furandicarboxylic acid with high yield under mild conditions. The method provided by the invention is green and pollution-free; the operation is convenient and the process is simple; the conversion rate of reactants and the selectivity of product 2,5-furandicarboxylic acid are both high.

Description

technical field [0001] The invention belongs to the technical field of organic chemistry, and in particular relates to a preparation method of 2,5-furandicarboxylic acid under mild conditions. Background technique [0002] As an important platform compound, 2,5-furandicarboxylic acid (FDCA) can not only be used in the fields of medicine and fine chemical industry, but also can be used as a monomer of polymer materials such as polyester and polyurethane. The synthetic polyester It is superior to PET in terms of gas barrier and thermal stability. At the same time, FDCA can be used to synthesize new polyester modifiers. Therefore, FDCA has great application potential, but there is no commercially feasible specific method for preparing this product. [0003] At present, the preparation method of FDCA is still in the laboratory stage, and there is no mature industrial preparation method. The most reported ones are noble metal catalytic oxidation, non-noble metal oxidation and AM...

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Problems solved by technology

[0002] As an important platform compound, 2,5-furandicarboxylic acid (FDCA) can not only be used in the fields of medicine and fine chemical industry, but also can be used as a monomer of polymer materials such as polyester and polyurethane. The synthetic polyester It is superior to PET in terms of gas barrier and thermal stability, and at the same time, FDCA can be used to synthesize new polyester modifiers, so FDCA has relatively great application potential, but there is no commercially feasible specific method for preparing this product.

In the patent CN105037303A, tungstic acid and quaternary ammonium molybdate are used as catalyst, water is used as solvent, and air / oxygen / hydrogen peroxide is used as oxidant to oxidize FDCA. The yield is more than 90%, but the catalyst is solid in this process. During the oxidation process, the self-assembly of 5-HMF is deposited on the surface of the catalyst, resulting in poor reusability of the catalyst, and the alkali is added to the reaction substrate at one time. Due to the instability of 5-HMF under alkaline conditions, it will increase the 5- The invalid loss of HMF, so the productive rate of FDCA can't reach more than 95%; In the patent CN110437190A, TEMPO is used as catalyst, inorganic acid and solid acid are used as promoter, and nitrous acid is used as promoter, and tertiary alcohol / water is used as solvent , using air / oxygen / hydrogen peroxide as oxidant to oxidize FDCA, the highest yield can reach about 90%, but this process requires a long reaction time, at least 24h, due to the poor solubility of intermediate products and FDCA; Zhang etc. (see: Pol.J.Chem.Technol., 2017,19,11-16) in the absence of catalyst addition, 5-HMF and potassium hydroxide were added to the reactor, and then by slowly adding hydrogen peroxide The method of oxidation preparation of FDCA, the optimal condition is 5-HMF: KOH: H 2 o 2 =1:4:8 (mol), reacting at 70°C for 15min, the FDCA yield is only 55.6%. Although this method is simple to operate, its selectivity is poor and the yield is low; Ji et al. (see: ACSSustainable Chem .Eng., 2018, 6, 11493–11501) using Au / TiO 2 As a catalyst, by adding hydrogen peroxide and sodium hydroxide, reacting at 97°C for 0.5h, the yield of FDCA can reach 99%, but this method uses Au as a catalyst, which is expensive and not suitable for large-scale production ; Chen et al. (see: ChemCatChem, 2018, 10, 361-365) used Cu / Co / Fe-loaded SBA-15 molecular sieve as a catalyst, directly used hydrogen peroxide to oxidize 5-HMF without adjusting the pH value, and its FDCA yield was less than 5 %

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