Magnetic Nanoparticle Immobilized N-Propylsulfamic Acid as a Recyclable and Efficient Nanocatalyst for the Synthesis of 2H-indazolo[2,1-b]phthalazine-triones in Solvent-Free Conditions: Comparison with Sulfamic Acid

Abstract

nanoparticles (MNPs-PSA) was used as an efficient andmagnetically recoverable catalyst for synthesis of 2H-Indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivativesfrom the three-component, one-pot condensation reaction of phthalhydrazide, aromatic aldehydes and cyclic1,3-diones, in good to excellent yields at 100 °C under solvent-free conditions. The catalyst was easilyseparated with the assistance of an external magnetic field from the reaction mixture and reused for severalconsecutive runs without significant loss of its catalytic efficiency. In order to compare, the synthesis of 2H-Indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives in the presence of catalytic amount of sulfamic acid(SA) under same reaction condition was also reported.Key Words : Magnetic nanoparticle, Nanocatalyst, N-Propylsulfamic acid, Condensation reaction, 2H-Inda-zolo[2,1-b]phthalazine-trionesIntroductionEnvironmentally benign, economical, practical, and effici-ent processes for catalyst separation and reuse have beenincreasingly important goals in the chemical communityfrom economic, safety, and environmental points of view.