BF3 bonded nano Fe3O4 (BF3/MNPs): an efficient magnetically recyclable catalyst for the synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives†
A simple and efficient procedure for the synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives has been developed by a one-pot three-component reaction of various aldehydes with malononitrile and 3-methyl-1-phenyl-2-pyrazoline-5-one in the presence of BF3/MNPs as a novel nanostructured, heterogeneous and reusable catalyst. In this research, BF3/MNPs nanoparticles were prepared at three calcination temperatures and characterized by various techniques. The characterization and optimization results show that the catalyst with a calcination temperature of 450 °C has the best catalytic activity. The nano-sized magnetite catalyst were recovered by simple separation with an external magnet and reused for several cycles without considerable loss of activity.