Efficient and safe conversion of 5-hydroxymethylfurfural to 5-hydroxymethyl-2-furancarbonitrile with hydroxylamine zinc chloride salt

Efficient and safe conversion of 5-hydroxymethylfurfural (HMF) to 5-hydroxymethyl-2-furancarbonitrile (HMFC) with hydroxylamine zinc chloride salt (ZnCl 2 ·2NH 2 OH) obtained from a novel method was developed. Without a catalyst, free NH 2 OH could react with HMF to produce HMFC with a yield of 41% at 55 °C. ZnCl 2 was an appropriate catalyst that increased HMFC yield to 64%. However, the reaction has a potential explosion safety hazard and a low effective utilization rate of NH 2 OH due to the easy decomposition property of free NH 2 OH. To address these issues, ZnCl 2 ·2NH 2 OH was prepared to serve as a hydroxylamine stabilizer, catalyst, and nitrogen source in the synthesis of HMFC. Therefore, NH 2 OH could be slowly released to participate in the reaction, slowing the invalid decomposition and increasing the utilization rate of elemental N. Under optimal conditions of n(HMF): n(NH 2 OH) = 1:1.5, 100 °C for 20 min with acetonitrile as solvent, the yield of HMFC was 100%. A plausible reaction mechanism for HMFC synthesis was also proposed.