Synthesis and kinetics of 2,5-dicyanofuran in the presence of hydroxylamine ionic liquid salts

Abstract

2,5-Dicyanofuran (DCF) is an important biomass-derived platform compound primarily used to prepare bio-based adiponitrile, which is the key precursor for the synthesis of nylon 66 and 1,6-hexanediisocyanate (HDI). In this study, one-pot, green and safe synthesis of DCF from 2,5-diformylfuran (DFF) and hydroxylamine ionic liquid salts was proposed. Eco-friendly hydroxylamine ionic liquid salts were used as the nitrogen source. Ionic liquid exhibited three-fold function of co-solvent, catalysis and phase separation. The conversion of DFF and yield of DCF reached 100% under the following optimum reaction conditions: temperature of 120 ℃ for 70 min, volume ratio of paraxylene: [HSO3-b-Py]·HSO4 of 2:1, and molar ratio of DFF:(NH2OH)2·[HSO3-b-Py]·HSO4 of 1:1.5. The reaction mechanism for the synthesis of DCF was proposed, and the kinetic model was established. The reaction order with respect to DFF and intermediate product 2,5-diformylfuran dioxime (DFFD) was 1.06 and 0.16, and the reaction activation energy was 64.07 kJ·mol−1and 59.37 kJ·mol−1 respectively. After the reaction, the ionic liquid was easy to separate, recover and recycle.