Silica Sulfuric Acid-Catalyzed One-Pot Synthesis, Mechanism, and Fluorescence Properties of 2-(2-arylquinolin-4-(1H)-ylidene)malononitriles

A mild, one-pot synthesis of 2-(2-arylquinolin-4-(1H)-ylidene)malononitriles is developed via the silica sulfuric acid-catalyzed tandem condensation of 2-aminoacetophenone with malononitrile and aromatic aldehyde in ionic liquid. It is proposed that malononitrile acted as not only a reactant but also a promoter in the interesting process. The fluorescence properties screening showed a new compound has high fluorescence quantum yield.