2,5-Furandicarboxaldehyde2,5-Furandicarboxaldehyde is an organic compound with the molecular formula C4H2O2. It consists of a furan ring with aldehyde groups on the 2 and 5 position. It is therefore classified as a dialdehyde.Synthesis2,5-Furandicarboxaldehyde is an oxidation product of 5-hydroxymethyl furfural, which in turn can be prepared from fructose. Alternatively, methods have been developed to convert fructose in one step to 2,5-furandicarboxaldehyde. The conversion from fructose to HMF and FDC can be performed relatively efficiently and following the principles of green chemistry. As such, these materials are often considered as "greener" bio-based alternatives.Applications2,5-Furandicarboxaldehyde can be used in the preparation of polyimine vitrimers. It can also be applied as an alternative to glutaraldehyde as crosslinking agent for covalent enzyme immobilisation.