چكيده به لاتين
In this work, a new core-shell magnetic silica functionalized with 3,4-diaminobenzoic acid nanocatalyst (Fe3O4@SiO2@PTS-DABA) was successfully prepared, characterized using different spectroscopic methods or techniques including FT-IR, FE-SEM, VSM, XRD, EDS and TGA. The Fe3O4@SiO2@PTS-DABA catalyst was applied, as a magnetic recoverable catalyst, for the synthesis of biologically active dihydropyranopyrazole and benzylpyrazolyl coumarin derivatives. These derivatives were prepared in the presence of Fe3O4@SiO2@PTS-DABA via a four-component reaction with yields of more than 90% under mild conditions. The Fe3O4@SiO2@PTS-DABA nanocatalyst is easily prepared from commercially available precursors at low cost, highly efficient, environmentally friendly, nontoxic and thermally stable. It shows a long life and can be reused for several catalytic cycles without significant loss of catalytic activity. Finally, a possible mechanism is proposed for preparation of these biologically active derivatives in the presence of this multifunctional magnetic catalyst. The structure of the products was identified by melting point as well as FT-IR and 1H NMR spectroscopic methods.
