Study On Synthesis Of N-containing Compounds From 5-Hydroxymethyl Furfural

In recent years,biomass is considered the only renewable resource on earth that can replace fossil resources for the production of fuel,materials and chemicals.As an important platform chemical derived from biomass,5-Hydroxymethyl furfural(HMF)is attracting more and more attention owning to the unique chemical structure with both hydroxyl and aldehyde groups.Nitrogen compounds can be widely used in the preparation of pharmaceutical intermediates,skin care products,pesticides,fine chemicals and synthetic polymers.Recently,biomass-based HMF to nitrogen compounds has become a hot spot.In this study we report a new reaction pathway in which the hydroxyl group was aminated via Ritter Reaction followed by direct reductive amination of the aldehyde group.Firstly,biomass-based HMF to N-acetyl-5-aminomethyl furfural(NAMF)in acetonitrile with the catalysis of acid was studied.According to the experiment results,the highest yield of NAMF was 90.1%when the reaction was operated under 100?for 3h with trifluoromethanesulfonic acid.However byproducts increased and the target product yield decreased with the higher temperature,longer time and higher content of acid;lower content of acid and weaker acid lead to lower NAMF yield.The reaction path of the reaction maybe proposed as:In the presence of strong acids,carbocation could be formed in HMF,and be attacked by nitrogen atom in nitrile,then NAMF was assembled with further water attack as well as proton transfer.Secondly,the direct reductive amination of NAMF with ammonia to N-acetyl-2,5-Bis(Aminomethyl)furan(NBAF)with Ni-Raney catalysts under mild conditions in methanol-liquid ammonia system was applied.Subsequently,hydrolysis was applied and BAF was obtained.90.3%NBAF yield could be obtained under the following reaction conditions:30 mL 30%NAMF solution,5 mL liquid ammonia,0.05 g Ni-Raney,15 bar H2,120 ?,3 h.Higher content of liquid ammonia,pH and content of water in the reaction system could lead to rapidly decline in NBAF yield.Best yield of product was 51.6%and obtained when the reaction was operated under 100 ? for 5 h in the hydrolysis reaction.Proposed mechanism of the reductive reaction was that the aldehyde group of NAMF was reductive aminated to primary amine with Ni-Raney catalysts under mild conditions in methanol-liquid ammonia system.Subsequently,hydrolysis was applied and 2,5-Bis(Aminomethyl)furan(BAF)was obtained.Above all,NAMF was prepared with HMF via Ritter reaction method and further BAF was producted by reductive amination reaction and hydrolysis reaction.This study presents a simple way for preparing BAF from renewable biomass based HMF,which enriches the biorefinery concept from biomass.