An efficient solvent mediated & use of metal-free catalyst strategy was developed for synthesis of FDCA over two steps. A simple & economical glucose-hydrothermally carbonized (Glu-HTC) catalyst was prepared and evaluated for synthesis of 2,5-Diformyl furan (DFF) from fructose & 5-hydroxymethylfurfural (HMF) in the 1^st step. DFF was then converted to FDCA using Pinnick oxidation in the 2^nd step. DFF was obtained in 82% & 86% yields from fructose & HMF respectively whereas FDCA was obtained in 94–95% yield from DFF. FDCA was thus formed in an overall yield of 78% and 81% from fructose & HMF respectively. This strategy eliminated use of expensive noble metals for FDCA synthesis and also intermediates such as HMFCA & FFCA were not observed after the reaction as DFF was completely oxidized to FDCA.

Graphical Abstract