METHOD FOR THE PREPARATION OF 2,5-FURANDICARBOXYLIC ACID (FDCA) Russian patent published in 2021 - IPC C07D307/68 

FIELD: chemistry.

SUBSTANCE: said invention relates to a method for producing 2,5-furandicarboxylic acid (FDCA) by oxidation of 5-hydroxymethyl-2-furfural (HMF), where the specified HMF is in solution, in an aprotic high-boiling polar solvent and water, characterized by a combination of: the first oxidation step, in which HMF is at least partially oxidized in said solution to form a first reaction mixture comprising at least one monatomic acid selected from a group including 5-hydroxymethylfuran-2-carboxylic acid (HMFA) and 5-formylfuran-2-carboxylic acid (FFCA) and optionally FDCA; the extraction step after the first oxidation step, in which the said high-boiling polar solvent is extracted from the first reaction mixture by an extraction solvent, where the above mentioned one or more monatomic acid remains in the aqueous phase, the second oxidation step, in which the above one or more monatomic acid is oxidized into FDCA.

EFFECT: technical result is a new method to produce 2,5-furandicarboxylic acid with a high recovery has been developed, which makes it possible to oxidize HMF in high-boiling polar solvents without the release or concentration of HMF before the oxidation stage.

8 cl, 3 dwg