synthesis of tri and four substituted imidazoles derivatives using zinc oxid nanotubes modified by sio2 as a powerful and reusable catalyst

in recent years, zinc oxid nanotubes have attracted much attention. the direct use of , zinc oxidnanotubes modified by sio2 as recoverable catalysts for organic reactions is very rare. the catalystswere characterized by xrd. the average particle size of zno catalysts is 57 nm and there are highdensitydefects on nanotubes surfaces . a simple and efficient method for the imidazol derivativessynthesis from the condensation benzil and ammonium acetate with substituted aromatic aldehydesin the presence of a catalytic amount zinc oxid nanotubes modified by sio2 is described. the reasonproposed for higher catalytic activity of zinc oxid nanotubes modified by sio2 is a combinationeffect of the small particle size and high-density surface defects. the practical and simple methodled to excellent yields of the tri and four substituted imidazoles derivatives under mild conditionsand within short times.