Syntheses of Symmetric and Unsymmetric Bis‐imidazole Derivatives Using Phase‐Transfer Catalysis

A convenient method for the preparation of symmetric and unsymmetric bisimidazole derivatives was established. The symmetric bisimidazolylmethane derivatives 1a–9a was prepared with 2‐substituted imidazole derivatives 1–9 as reaction materials. However, the symmetric and unsymmetric bisimidazolylmethane derivatives 10a–12a and 10b–12b was obtained, respectively. With 4‐position with the azo‐groups imidazole derivatives 10–12 were used as reaction materials. All these compounds have been structurally characterized by the NMR, ESI‐MS, and EA. And 8a and 12a were also characterized by the X‐ray single crystal diffusion.