New MCRs in Ionic Liquid: Green Synthesis and Biological Activity Investigation of New Pyrazoloazepines: Application of Ag/Fe3O4/CdO@MWCNT MNCs in Reduction of Organic Pollutant

Abstract

In this research we have synthesized new derivatives of dihydrobenzopyrazoloazepine in high yields using multicomponent reaction of anilines, oxalylchloride, alkyl bromides, activated acetylenic compounds, and hydrazine in the presence of Ag/Fe3O4/CdO@MWCNTs MNCs as a high-performance catalyst in ionic liquid at room temperature. The Ag/Fe3O4/CdO@MWCNTs MNCs were synthesized using ionic liquid 1-Octhyl-3-methyl imidazolium bromide ([OMIM]Br) as a stabilizer and soft template. Because of having NH group in the synthesized compounds, the antioxidant property of some synthesized dihydrobenzopyrazoloazepine was investigated by diphenyl-picrylhydrazine (DPPH) radical trapping and power of ferric reduction experiment. Also, the catalytic activity of the green synthesized Ag/Fe3O4/CdO@MWCNTs MNCs was evaluated in the reduction of organic pollutants, such as 4-nitrophenol (4-NP) in water under mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for removing organic pollutants within a few seconds. A short time of reaction, high yields of product and easy separation of catalyst and products are some advantages of this procedure. HIGHLIGHTS Ionic liquids (ILs) are one of the important examples of green solvents with the capacity to solvate an array of inorganic and organic substrates and vanishingly small vapor pressures. ‘ILs are promising substitutes for volatile organic solvents (VOCs).’ The present procedure avoids the use of toxic solvents. Benzazepines, which have a seven-membered aza-heterocyclic fused aromatic ring, are of interest because of their biological activity and use as building blocks for natural product synthesis and drug discovery.