Abstract: The present invention relates to a process for the production of 2,5-furandicarboxylic acid (FDCA) via oxidation of 5-hydroxymethyl-2-furfural (HMF), said HMF being present in a solution in a high-boiling polar solvent and water. The process is characterized by the combination of —a first oxidation step wherein the HMF is at least partly oxidized in said solution to yield a first reaction mixture comprising at least one monoacid selected from the group consisting of -hydroxymethylfuran-2-carboxylic acid (HMFA), 5-formylfuran-2-carboxylic acid (FFCA) and, optionally, FDCA —an extraction step after the first oxidation step wherein said high-boiling polar solvent is extracted from said first reaction mixture by means of an extraction solvent, wherein said at least one monoacid remains in an aqueous phase, —a second oxidation step wherein said at least one monoacid is oxidized to FDCA.

Abstract: The present invention relates to a process for the production of 2,5-furandicarboxylic acid (FDCA) via oxidation of 5-hydroxymethyl-2-furfural (HMF), said HMF being present in a solution in a high-boiling polar solvent and water. The process is characterized by the combination of—a first oxidation step wherein the HMF is at least partly oxidized in said solution to yield a first reaction mixture comprising at least one monoacid selected from the group consisting of -hydroxymethylfuran-2-carboxylic acid (HMFA), 5-formylfuran-2-carboxylic acid (FFCA) and, optionally, FDCA—an extraction step after the first oxidation step wherein said high-boiling polar solvent is extracted from said first reaction mixture by means of an extraction solvent, wherein said at least one monoacid remains in an aqueous phase,—a second oxidation step wherein said at least one monoacid is oxidized to FDCA.