Room Temperature Ionic Liquid Promoted Improved and Rapid Synthesis of 2,4,5-Triaryl Imidazoles from Aryl Aldehydes and 1,2-Diketones or α-Hydroxyketone.

An improved and rapid one-pot synthesis of 2,4,5-triaryl imidazoles in a room temperature ionic liquid is described, which does not need any added catalyst. Different ionic liquids based on 1-n-butyl and 1,3-di-n-butyl imidazolium salts were screened and their efficacy in terms of acidity and polarity have been correlated with yields and reaction period. The one-pot methodology resulting in excellent isolated yields in short reaction times is characterized by simple work up procedures and efficient recovery and recycling of the ionic liquid, which acts as a promoter.