From Lignocellulosic Biomass to Furans via 5-Acetoxymethylfurfural as an Alternative to 5-Hydroxymethylfurfural

A facile pathway to furan derivatives from lignocellulosic biomass via 5-acetoxymethylfurfural (AMF) was developed. AMF possesses advantageous properties due to its less-hydrophilic acetoxymethyl group relative to the hydroxymethyl group of 5-hydroxymethylfurfural (HMF). The hydrophobicity and chemical stability of AMF allowed practical isolation and purification to afford a highly pure product of up to 99.9%. AMF was produced in good to excellent yields under mild conditions from 5-chloromethylfurfural (CMF) and alkylammonium acetates, both of which could be obtained directly from lignocellulosic biomass. Heterogeneous reactions with polymer-supported alkylammonium acetates were also established; this showed the feasibility of a continuous process for this pathway. AMF could be transformed into various promising furanic compounds, such as 2,5-furandicarboxylic acid (FDCA), 2,5-furandimethanol (FDM), and 5-hydroxymethyl-2-furanoic acid (HFA), in high yields.