Synthesis of bis(amino)furans from biomass based 5-hydroxymethyl furfural

In this study we report a new reaction pathway in which the hydroxyl and the aldehyde groups of 5-hydroxymethyl furfural were aminated respectively. Hydroxyl group was aminated via Ritter reaction followed by direct reductive amination of aldehyde group. For the Ritter reaction of 5-hydroxymethyl furfural, mixture of trifluoromethane sulfonic acid and phosphoric anhydride showed good performance and the intermediate N-acyl-5-aminomethyl furfural with the highest yield of 89.1 wt% was obtained. Optimization of direct reductive amination of 2,5-bis(aminomethyl) furan was conducted and a yield of 45.7 wt% was achieved. This study presents a simple way for preparing bis(amino)furans from renewable biomass based 5-hydroxymethyl furfural, which enriches the biorefinery concept from biomass.