Ionic‐liquid‐promoted dual hydrogen‐bond activation strategy enabling the synthesis of diverse 2‐pyridone‐fused uracils

The synthesis of diverse 2‐pyridone‐fused uracils has been accomplished using the ionic liquid [bmim]BF 4 as a dual hydrogen‐bond (HB) activator. A [4 + 2] annulation–dehydration cascade reaction between 6‐methyluracil‐5‐carbaldehydes and isocyanates was promoted through a HB‐mediated strategy based on non‐covalent interactions (NCIs). This protocol provides an operationally simple procedure that eliminates the use of strong bases, enabling straightforward access to structurally intriguing 2‐pyridone‐fused uracils—valuable scaffolds with promising potential in drug discovery.