The Knoevenagel reaction of isatins with malononitrile or ethyl cyanoacetate catalyzed by SBA-15 silica-supported Schiff base in aqueous medium

This is the authors' abstract. We don't add key points for this paper.

In this work, a 2-phenyl-2H-1,2,3-triazole-4-yl structure was grafted onto SBA-15 silica utilizing 3-aminopropyltriethoxysilane (APS) as a coupling reagent to create an SBA-15 silica-supported Schiff base. Fourier transform infrared spectroscopy (FT-IR), high and low angle XRD, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to examine the structure of the produced catalysts. The characterization results showed that the Schiff base was successfully attached on the SBA-15 silica's surface and that, even after chemical grafting, the silica's hexagonally organized mesoporous structure was preserved. The Knoevenagel condensation reaction of isatins with malononitrile or ethyl cyanoacetate in an aqueous solution was effectively carried out with the help of this catalyst. Furthermore, after six runs, the catalyst can be recycled without experiencing a noticeable decrease of activity.