Synthesis and Characterization of Imidazole Derivatives

¹H (500 MHz) and ¹³C NMR (125 MHz) spectra were recorded on a Bruker Avance Digital 500 spectrometer. Melting points were determined on a microscopic melting point apparatus (Stanford Research Inc. MPA 100 automated melting point apparatus). High-resolution mass data were recorded using electronic ionization (HRMS-EI, magnetic sector-electric sector double focusing mass analyzer) at Korea Basic Science Institute, Daegu Center, Korea. All reactions were carried out in a sealed tube under microwave irradiation (CEM, Discover LabMate) and the reaction temperature was maintained by an external infrared sensor. The products were isolated by TLC (a glass plate coated with Kieselgel 60 GF₂₅₄, Merck). 2-(2-Bromoaryl)- and 2-(2-bromovinyl)-4,5-diaryl-1H-imidazoles 1 were synthesized from the corresponding aldehydes and 1,2-diarylethane-1,2-diones (see ESI†).^{12,13 (link)} 2-Aminobenzimidazoles 2 were prepared from 1,2-phenylenediamines and cyanogen bromide by known methods.^{19 (link)} Other commercially available organic and inorganic reagents were used without further purification.