Iron(III) Sulfate-Mediated Synthesis of 2,5-Furandicarboxylic Acid Dimethyl Ester from Galactaric Acid

Abstract

2,5-furandicarboxylic acid (FDCA) is one of the most studied bio-based monomers, being considered the best substitute for fossil-derived terephthalic acid in plastic production. FDCA is employed in the preparation of polyethylene furanoate (PEF), demonstrating superior mechanical and thermal proprieties compared to the widely used polyethylene terephthalate (PET). Nevertheless, FDCA synthesis mostly relies on the oxidation of the bio-based platform chemical hydroxymethyl furfural (HMF), whose notoriously instable nature renders FDCA yield and industrial scale-up production complicated. On the contrary, FDCA esters are less studied, even though they have greater solubility in organic media, which would favor their isolation and potential application as monomers for PEF. On these premises, we report herein an alternative green synthetic approach to FDCA methyl ester (FDME) using galactaric acid as the substrate, dimethyl carbonate (DMC) as the green media, and Fe2(SO4)3 as the heterogeneous Lewis acid. Optimization of the reaction conditions allowed the selective production of FDME in a 70% isolated yield; product purification was achieved via flash column chromatography over silica. Furthermore, it was possible to employ up to 5.0 g of galactaric acid in a single reaction, leading to a good isolated yield of FDME.

Furandicarboxylate Polyesters: A Comprehensive ADMET Study of a Novel Class of Furan‐Based α,ω‐Diene Monomers

“…FDME was synthesized in large scale from galactaric acid using a previously reported procedure [6,30] . Four commercially available alcohols with a terminal olefin – allyl alcohol, but‐3‐en‐1‐ol, hex‐5‐en‐1‐ol and dec‐9‐en‐1‐ol – were selected to prepare α,ω‐diene monomers, by transesterification reaction.…”

“…FDME was synthesized in large scale from galactaric acid using a previously reported procedure. [6,30] Four commercially available alcohols with a terminal olefin -allyl alcohol, but-3-en-1-ol, hex-5-en-1-ol and dec-9-en-1-ol -were selected to prepare α,ωdiene monomers, by transesterification reaction. The purpose was to investigate the influence of the alkene chain length on the rigidity and thermal properties of the resulting polymers.…”

“…It is noteworthy that the FDME employed as starting material in this study was prepared according to our recently published procedure starting from galactaric acid in a one-pot procedure utilizing dimethyl carbonate (DMC) chemistry (Scheme 1). [6,30] The soprepared monomers were then subjected to ADMET polymerisation under various conditions, offering precise control over the thermal properties of the resulting polymers. The use of green solvents in the ADMET polymerisation was also explored.…”

Reaction Pathways in Carbonates and Esters

“…More recently also other biobased platform chemicals such as galactaric acid have recently showed to cyclise via DMC chemistry. [71] The alkylation of isosorbide and its epimers (isomannide and isoiodide), with DACs has also been the focus of extensive investigations. [72] The secondary hydroxyls of this cyclic sugar could be easily methylated at the reflux temperature of DMC (Figure 5).…”