Efficient synthesis of 5-methyl-2-furancarboxylic acid via selective hydrogenolysis of bio-renewable 5-hydroxymethyl-2-furancarboxylic acid on Pd/C catalysts at ambient temperature

Abstract

5-Methyl-2-furancarboxylic acid (MFA) is an important substituted furoic acid with versatile applications. However, its synthesis processes are not green and efficient. Here, we report a novel route to the sustainable synthesis of MFA from bio-renewable 5-hydroxymethyl-2-furancarboxylic acid (HMFA) by the direct cleavage of the C–OH bond in HMFA at ambient temperature. Active carbon (C)-supported Pd catalysts exhibited high efficiency and stability in HMFA hydrogenolysis to MFA, providing a high yield of 94.5% at 30 °C and 3.0 MPa H₂ in tetrahydrofuran. Such a high efficiency of Pd/C was found to be related to the strong adsorption of HMFA on the C support surfaces, most likely via their π–π interactions. This work provides an efficient strategy for the selective cleavage of the α-C–OH bonds in the furan ring under mild conditions and the sustainable production of MFA and its derivatives from biomass resources.