One-Step Reductive Amination of 5-Hydroxymethylfurfural into 2,5-Bis(aminomethyl)furan over Raney Ni

Simultaneous reductive amination of C=O and C-OH in 5-hydroxymethylfurfural (HMF) into C-NH2 in 2,5-bis(aminomethyl)furan (BAMF) is challenging. In this work, reductive amination of C=O in HMF was firstly studied, in which HMF can be converted into 5-hydroxymethyl furfurylamine (HMFA) with a 99.5 % yield over Raney Co catalyst. BAMF was then directly synthesized with 82.3 % yield from HMF over Raney Ni catalyst at 160 degrees C for 12 h. An even higher yield of 88.3 % could be obtained through a stepwise reductive amination process, in which the reaction started at 120 degrees C for the first 2 h over Raney Co mainly for amination of C=O and then continued at 160 degrees C for another 10 h over Raney Ni mainly for amination of C-OH. Under optimized reaction conditions, the catalyst could be reused four times without obvious loss in catalytic performance. XRD and XPS characterization of the reused catalyst indicated that the formation of Ni3N and the adsorption of alkyl amines could be the main reasons for the deactivation of the catalyst. Moreover, plausible reaction pathways were proposed to originate the detected by-products according to the kinetic profiles.

Automated summary

The simultaneous reductive amination of C=O and C-OH in HMF to form BAMF is challenging, and this study demonstrates methods for achieving high yields through a stepwise reductive amination process.