a green one-pot three-component synthesis of 10,11-dihydro chromeno[4,3-b]chromene-6,8(7H,9H)-dione derivatives using a Fe3O4@SIO2-PMA magnetic nanocatalyst under reflux conditions

An efficient and environmentally benign procedure for the synthesis of 10,11-dihydrochromeno [4,3-b]chromene-6,8(7H,9H)-dione derivatives has been developed by a one-pot three-component reaction of 4-hydroxycoumarin, aldehydes, and cyclic 1,3-dicarbonyl compounds in the presence of Fe3O4@SiO2-imid-PMAn nanoparticles as magnetic catalysts under reflux conditions in water. This new procedure has notable advantages such as operational simplicity, excellent yields, short reaction time, and absence of any tedious workup or purification. In addition, the excellent catalytic performance in a water medium and the easy preparation, thermal stability and separation of the catalyst make it a good heterogeneous system and a useful alternative to other heterogeneous catalysts. Also, the catalyst can be easily recovered by a magnetic field and reused for six consecutive reaction cycles without significant loss of activity

Keywords:

MCR , 10 , 11-Dihydrochromeno[4 , 3-b]chromene-6 , 8(7H , 9H)-dione derivatives , Green synthesis , Heterogeneous magnetic catalyst , Magnetic separation