synthesis of 4,4'-(aryl methylene)bis(3-methyl-1h-pyrazol-5-ol)s and synthesis of hexahydroquinohine derivatives by magnetic functionalized based on nano fe3o4 as a catalysts

Catalysts in chemical reactions improve the reaction conditions, increase the speed and yield of the products. so, they play a prominent role in various industries such as the chemical industry, petroleum industry, and pharmaceutical chemistry. in this work, the catalytic activity of nano fe3o4@sio2@si(ch2)3@melamine@so3h was evaluated for synthesis of 4,4'-(aryl methylene)bis(3-methyl-1h-pyrazol-5-ol)s via one-pot reactions of 2 mmol phenylhydrazine, 2 mmol ethylacetoacetate and aryl aldehyde derivatives under solvent-free condition and synthesis of hexahydroquinohine derivatives via one-pot reactions of aryl aldehyde derivatives, dimedone, ethylacetoacetate and ammonium acetate under solvent-free condition.magnetic fe3o4@sio2@si(ch2)3@melamine@so3h was prepared via a simple method and to identify the synthesized catalysts, we used analyzes such as infrared spectroscopy (ft-ir), x-ray diffraction (xrd), field emission scanning electron microscopy (fe-sem), transmission electron microscopy (tem), thermal gravimetric analysis (tga), and vibrating sample magnetometer (vsm). this protocol has advantages such as high yields of the products, solvent free. most importantly, the catalyst can be conveniently recovered from the reaction mixture by using external magnet and reused for at least three times without significant decrease in catalytic activity.