Efficient Synthesis of 2,5-Dicyanofuran from Biomass-Derived 2,5-Diformylfuran via an Oximation–Dehydration Strategy

Aromatic dinitriles show promise as a pivotal building block in polymer and pharmaceutical chemistry, and their production from biomass-based alcohols or aldehydes is highly desirable. In this work, for the first time, 2,5-dicyanofuran was efficiently synthesized from biomass-derived 2,5-diformylfuran via a two-step procedure. 2,5-Diformylfuran was first converted to 2,5-diformylfuran dioxime with 90% isolated yield in water. Hydroxylamine instead of ammonia used as nitrogen source is the key to this strategy, which avoids the polymerization reaction of intermediate aldimine. The subsequent dehydration reaction of 2,5-diformylfuran dioxime afforded 2,5-dicyanofuran in 82% isolated yield over an effective and recyclable solid acid catalyst Amberlyst-15. This approach demonstrates the feasibility of synthesis of reactive dinitriles from dialdehydes without using toxic cyanides or halides.