Design, synthesis, and application of 1H-imidazol-3-ium trinitromethanide {[HIMI]C(NO2)3} as a recyclable nanostructured ionic liquid (NIL) catalyst for the synthesis of imidazo[1,2-a]pyrimidine-3-carbonitriles

Abstract

In this study, 1H-imidazol-3-ium trinitromethanide (1) {[HIMI]C(NO2)3} as a green and recyclable catalyst based on nanostructure ionic liquid (NIL) was designed, synthesized, fully characterized by various analysis techniques, and applied as catalyst for the synthesis of 4-amino-1,2-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile derivatives via one-pot three-component condensation reaction. The reaction tolerates a wide range of electron-donating and electron-withdrawing substituents on aldehydes with malononitrile and 2-aminobenzimidazole at 50 °C under neat conditions. The described reaction is compatible with the green chemistry disciplines and their main advantages are short reaction time, high yields, simplicity of product isolation, and clean reaction profile. Additionally, the NIL catalyst (1) {[HIMI]C(NO2)3} can be readily recovered in the reaction vessel using a mixture of EtOAc/H2O (1:1) and reused for four consecutive runs without a significant loss in catalytic activity. The present study can open up a new and promising insight in the course of rational design, synthesis and applications of nanostructured task-specific ionic liquids (NTSILs) for numerous green purposes.