Green and efficient synthesis of benzoquinoline compounds by a three-component reaction in the presence of a cellulose-based sulfonated magnetic nanocatalyser under ultrasonic conditions

In this study, a green and efficient method for the synthesis of benzoquinoline compounds has been described through the reaction of malononitrile derivatives with different aldehydes and naphthylamine in the presence of heterogeneous functionalized nanocellulose catalyst with sulphonic groups (Fe3O4@ Cellulose-OSO3H) is described. Synthesis of benzoquinoline is proceed very well in the presence of Fe3O4@ Cellulose-OSO3H under solvent-free conditions using ultrasonic waves. The Fe3O4@ Cellulose-OSO3H can be recoverd and reused at least four consecutive times under optimized conditions with a slight decrease in its catalytic activity. High to quantitative yields of the desired products, low loading of the catalyst, short reaction times at ambient temperature, reusability of the catalysts, and avoiding the use of toxic solvents are significant advantages of this green protocol.