Scheme 5. Scope and Limitations of Imidazole Formation with Various Nitriles.

Reaction conditions: To amide 1 (0.2 mmol) and 2-NO₂-pyr (0.4 mmol) in R³CN (2 mL) at 0 °C was added Tf₂O (0.4 mmol). After 15 min, the reaction mixture was warmed to 23 °C for 2 h. Isolated yields are shown.