标题：Solvent Free One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles Catalyzed by Secondary Amine Based Ionic Liquid and Defective Keggin Heteropoly Acid
摘要：Secondary amine based ionic liquid and defective Keggin type
heteropoly acid (HPA) are separately used for efficient one-pot four-component
synthesis of 1,2,4,5-tetrasubstituted imidazoles assisted by microwave (MW).
Eco-friendly solvent free procedure, short reaction time, high yield of
products and reusability of catalysts are important features of the synthesis.
A comparative study on the efficiency of the two catalysts is reported. This
work further demonstrates the alternate use of urea, instead of often used
ammonium acetate, as source of nitrogen.
