An Efficient One‐Pot Synthesis of 7,7‐Dimethyl‐2‐(2‐oxo‐2 H ‐chromen‐3‐yl)‐4‐aryl‐7,8‐dihydroquinolin‐5(6 H )‐one Derivatives Using Chitosan–SO 3 H as Biodegradable Organocatalyst

Chitosan sulfonic acid (CS–SO 3 H), a biodegradable green catalyst, was found to be an impressive system for one‐pot four‐component reaction of different aromatic aldehydes, 3‐acetylcoumarin, dimedone, and ammonium acetate leading to 7,7‐dimethyl‐2‐(2‐oxo‐2 H ‐chromen‐3‐yl)‐4‐aryl‐7,8‐dihydroquinolin‐5(6 H )‐one under solvent‐free condition. This methodology produces diverse superiorities such as operational simplicity, short reaction time, and high yield. Further, the catalyst can be reused for four times without any noticeable decrease in the catalytic activity.