An efficient and green protocol for synthesis of 3,3'-arylmethylene-bis(4-hydroxyquinolin-2(1H)-ones) using potassium phthalimide as reusable catalyst

A simple, efficient and eco-friendly procedure has been developed using potassium phthalimide as catalyst for the synthesis of 3,3'-arylmethylenebis(4-hydroxyquinolin-2(1h)-ones) in aqueous ethanol. the present methodology offers several advantages such as operational simplicity, use of potassium phthalimide as a green, non-toxic, inexpensive and reusable catalyst, high yields and environmentally benign reaction conditions.