nano-ferrite znfe2o4 as efficient and re-usable catalyst for the synthesis of 4h-chromenes and 4h-pyrano[2,3-c] pyrazoles

Nano-magnetic ferrite znfe2o4 among other magnetic nanoparticles include fe2o3, fe3o4, ni(0.7)zn(0.3)fe2o4 and mn(0.7)zn(0.3)fe2o4 was explored as an efficient catalyst for the synthesis of various 4h-chromenes and 4h-pyrano[2,3-c]pyrazoles in etoh/h2o (2:1) via an easy and green procedure. the desired products were obtained in high yields via a three-component reaction between aromatic aldehydes with malononitrile and 5,5-dimethyl-cyclohexane-1,3-dione or 3-methyl-1-phenyl-2-pyrazolin-5-one at room temperature. the structure of this catalyst was fully characterized via fourier transform infrared spectroscopy, xrd, sem, tem, edax, and vsm. the employed nanocatalyst was easily recovered using a magnetic field and reused ten times (in subsequent runs) without observation a significant decrease in activity.