Catalytic Amidation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxamide over Alkali Manganese Oxides

2,5-Furandicarboxamide was firstly synthesized in yield of 85% via catalytic oxidative amidation of 5-hydroxymethylfurfural with aqueous NH3 over alkali manganese oxides of α-MnO2/NaxMnO2. The intermediates of 5-hydroxymethyl-furonitrile, 2,5-dicyanofuran, and 5-cyano-2-furancarboxamide were verified and their reactivities were further examined. The kinetic analysis results showed that the transformation of intermediate product of 5-cyano-2-furancarboxamide to 2,5-furan-dicarboxamide is a slower step, which is closely relative to the reaction temperature and basicity of catalyst.