| abstract |
The disclosure pertains to a process for oxidation of furan aldehydes such as 5-hydroxymethyl)furfural (HMF) and derivatives thereof such as 5-(alkoxymethyl)furfural (AMF), 5-(aryloxymethyl)furfural, 5-(cycloalkoxy-methyl)furfural and 5-(alkoxycarbonyl)furfural compounds in the presence of dissolved oxygen and a Co(II), Mn(II), Ce(III) salt catalyst or mixtures thereof. The products from HMF can be selectively chosen to be predominantly 2,5-diformylfuran (DFF), particularly by inclusion of an aliphatic ketone, like methyl ethyl ketone, or can be further oxidized to 2,5-furandicarboxylic acid (FDCA) by the omission of methyl ethyl ketone and inclusion of bromide. When the reactant is an ether derivative of HMF the products are surprisingly ester derivatives where either both the ether and aldehyde functional groups have been oxidized or just the ether function group thereby producing one or both of 5-ester-furan-2-acids (i.e., 5-alkoxycarbonylfurancarboxylic acids) or 5-ester-furan aldehydes, (i.e., -alkoxycarbonylfurfurals a. k. a, 5-(alkoxycarbonyl)furfural). (I). |