2,5-Furandicarboxylic acid (FDCA) is a promising biobased aromatic monomer that can be used to synthesize novel biobased polymeric materials, but efficient synthesis of FDCA is still a great challenge to date. In this study, a two-step method is proposed to synthesize FDCA directly from fructose under mild conditions without 5-hydroxymethylfurfural (HMF) separation, using commercially available catalysts. In the first step, HMF was formed in 97.1% HPLC yield by dehydrating fructose in DMSO under the catalysis of Amberlyst-15 at 120 °C for 1 h. In the second step, the in situ formed HMF was oxidized in 3/1 (w/w) alkaline (K₂CO₃) H₂O/DMSO medium under the catalysis of Pt/C at 100 °C for 10 h to form FDCA in 91% HPLC yield. The overall yield of FDCA from fructose reached as high as 88.4%. The conversions of HMF to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) and HMFCA to 5-formyl-2-furancarboxylic acid (FFCA) are fast, but FFCA to FDCA is a slow and rate-limiting step in HMF oxidation. H₂O/DMSO ratio, alkali type, alkali/HMF ratio, and reaction temperature are important factors affecting the reaction rate and selectivity. The synergy between alkaline aqueous solution and DMSO is the key to high FDCA yield.

中文翻译：

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在没有5-羟甲基糠醛（HMF）分离的情况下从果糖高效两步合成2,5-呋喃二甲酸：在温和条件下在碱性H ₂ O / DMSO混合溶剂中原位氧化HMF

2,5-呋喃二甲酸（FDCA）是一种有前途的生物基芳香族单体，可用于合成新型生物基聚合物材料，但迄今为止，FDCA的有效合成仍然是一个巨大的挑战。在这项研究中，提出了一种两步法，可以使用市售催化剂在温和条件下直接从果糖合成FDCA，而无需进行5-羟甲基糠醛（HMF）分离。第一步，在Amberlyst-15的催化下于120°C的条件下，通过将果糖在DMSO中脱水，以97.1％的HPLC产率形成HMF。在第二步中，将原位形成的HMF在3/1（w / w）碱性（K ₂ CO ₃）H _2中氧化O / DMSO介质在Pt / C的催化下于100°C加热10 h以形成FDCA，HPLC产率为91％。来自果糖的FDCA的总产率高达88.4％。HMF转化为5-羟甲基-2-呋喃甲酸（HMFCA）和HMFCA转化为5-甲酰基-2-呋喃羧酸（FFCA）的速度很快，但是FFCA转化为FDCA是HMF氧化过程中的一个缓慢且限速的步骤。H ₂ O / DMSO比，碱类型，碱/ HMF比和反应温度是影响反应速率和选择性的重要因素。碱性水溶液和DMSO之间的协同作用是高FDCA产量的关键。