Magnetic nanoparticle immobilized N-propylsulfamic acid: The efficient, green and reusable nanocatalyst for the synthesis of 3,3-Arylidene bis(4-Hydroxycoumarin) derivatives

N-Propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) was investigated as an efficient and magnetically recoverable catalyst for the one-pot synthesis of 3,3-Arylidene bis(4-Hydroxycoumarin) derivatives from the reaction of coumarin with variety aromatic aldehydes in high to excellent yield at room temperature under solvent-free conditions. The magnetic nanocatalyst (MNPs) can be readily recovered by applying an external magnet device and reused for at least 10 reaction runs without considerable loss of its activity. The advantages of this protocol are the mild reaction conditions, operational simplicity, practicability, short reaction times, and high to excellent product yields.