Employing Cu@Fe₃O₄/SiO₂@MWCNTs as New Catalyst for the Green Synthesis of New Pyridopyrroloindoles Using Multicomponent Reactions of Isatins

ABSTRACT By using a multicomponent reaction involving isatins, diamines or aminoalcohols, activated acetylenic compounds, haloketones, and ammonium acetate in aqueous media in the presence of Cu@Fe 3 O 4 /SiO 2 @MWCNTs as new catalyst, the novel pyridopyrroloindole was produced in high yields. This catalyst was produced by employing Petasites hybridus rhizome water extract as a green media and moderate base. The pyridopyrroloindole derivatives were newly synthesized compounds, and their antioxidant properties were assessed using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical trapping and ferric reducing ability of plasma (FRAP) experiments. The pyridopyrroloindole 6b showed higher performance than butylated hydroxytoluene (BHT) and tert‐butylhydroquinone (TBHQ) better results. This method is used to make pyridopyrroloindole derivatives, and it has the advantages of a quick reaction, high yields, and the ability to separate the products easily.