Highly efficient two-step synthesis of 2,5-furandicarboxylic acid from fructose without HMF separation: in-situ oxidation of HMF in alkaline aqueous H2O/DMSO mixed solvent under mild conditions.
作者：Guangyu Chen, Linbo Wu*, Hong Fan, Bo-geng Li.
關鍵字：2,5-furandicarboxylic acid, 5-hydroxymethyl furan, fructose, dehydration, oxidation, one-pot synthesis
論文來源：期刊
具體來源：Ind Eng Chem Res 2018, 57, 16172?16181 10.1021/acs.iecr.8b03589
發表時間：2018年
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.