2,5-Furandicarboxylic acid,tetrahydro-

• CAS: 6338-43-8
• Catalog Number: ACM6338438
• Category: Main Products
• Molecular Weight: 160.12472
• Molecular Formula: C₆H₈O₅
• Synonyms: 2,5-Furandicarboxylic acid, tetrahydro-;Hexaric acid, 2,5-anhydro-3,4-dideoxy-;2,5-Anhydro-3,4-dideoxyhexaric acid;NSC 40743
• IUPAC Name: Tetrahydrofuran-2,5-dicarboxylic acid
• Boiling Point: 425.5ºC at 760 mmHg
• Flash Point: 186.7ºC
• Density: 1.535 g/cm³
• Exact Mass: 160.03700

Case Study

Tetrahydrofuran-2,5-dicarboxylic acid as a Renewable Feedstock for Sustainable Adipic Acid Production

Castilla-Acevedo, Samir F., et al. Catalysis Today 436 (2024): 114722.

This study evaluated tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)-a hydrogenated derivative of furandicarboxylic acid (FDCA)-as a platform molecule for Adipic acid (AA, key monomer for nylon-6,6) production via hydrodeoxygenation (HDO) over Pt-MOx catalysts. THFDCA thus represents a promising bio-derived intermediate for green AA production when coupled with appropriately designed Pt-Mo catalysts.
Catalysts and Calculations: A series of Pt-MOx/TiO2 and Pt/MOx catalysts (MOx = WOx, MoOx, ZrOx) were synthesized and tested in aqueous HDO reactions. Catalysts containing both Pt and Mo exhibited unique synergy: at 180 °C, they favored carboxyl group reduction to alcohols, while at 220-240 °C, selectivity shifted toward AA. DFT calculations and kinetic Monte Carlo simulations revealed that this temperature-dependent behavior arises from competitive adsorption of the intermediate 2-hydroxyadipic acid (2-HAA) on MoOx surface sites-oxygen vacancies (O-VAC) promote C=O adsorption at lower temperatures, while Brønsted acid sites (BAS) favor alcohol-group adsorption above 200 °C, enabling acid-catalyzed dehydration to AA.
Key Results: Optimal AA yields of 65% were achieved at 240 °C using Pt-MoOx/TiO2 (5:1 Mo:Pt) and 0.1 wt% Pt/MoO3. Increasing Mo loading suppressed alcohol formation and enhanced AA selectivity, with yields rising from 24% (1:1 Mo:Pt) to 56% (5:1 Mo:Pt). Pt-Mo proximity proved critical; physical mixtures of Pt/TiO2 and MoOx/TiO2 gave <2% AA yield. High carbon balance (>90%) and minimal decarbonylation were maintained, demonstrating efficient preservation of carboxyl groups.

Tetrahydrofuran-2,5-dicarboxylic acid as a Renewable Platform for Metal-Free Adipic Acid Synthesis

Gilkey, Matthew J., et al. ACS Catalysis 7.10 (2017): 6619-6634.

This study demonstrates that tetrahydrofuran-2,5-dicarboxylic acid (THFDCA)-a hydrogenated derivative of furandicarboxylic acid (FDCA)-can be efficiently converted to adipic acid (AA) using a metal-free catalytic system comprising hydriodic acid (HI) and molecular H2 in an organic acid solvent.
Reaction Mechanism: The reaction proceeds via HI-mediated ring-opening of THFDCA through protonation and iodide attack, forming an iodo-intermediate that undergoes subsequent hydrogenolysis. Detailed kinetic studies and DFT calculations elucidated the mechanism: HI acts bifunctionally as both a strong acid and a source of nucleophilic iodide, while H2 participates directly in the rate-determining C-I bond hydrogenolysis. The organic acid solvent (propionic or acetic acid) plays a critical role by facilitating substrate protonation, whereas water inhibits the reaction by competing as a stronger base.
Key Results:
· Up to 89% adipic acid yield was achieved at 160 °C using 0.3 M HI and 500 psi H2 in propionic acid. The reaction exhibits ~1st-order dependence on THFDCA and H2, and ~2nd-order dependence on HI, consistent with a mechanism where HI-mediated ring opening is followed by H2-assisted C-I hydrogenolysis.
· Water strongly suppresses AA formation: increasing water concentration above 0.2 M fraction leads to a sharp decline in yield, as confirmed by computational thermodynamics showing THFDCA protonation becomes endergonic.
· The system selectively cleaves ether C-O bonds without reducing carboxylic acid groups, preserving the diacid functionality essential for AA production.