نتایج جستجو برای: sulfonic acid functionalized silica sio2 pr so3h
تعداد نتایج: 835668 فیلتر نتایج به سال:
Two highly efficient protocols for the production of bis-coumarins under solvent-free conditions have been introduced. The reaction of 4-hydroxycoumarin (2 eq.) with arylaldehydes (1 eq.) using phthalimide-N-sulfonic acid (PhtSA) or isatin-N-sulfonic acid (IsSA), as solid-acid catalysts, afforded the mentioned compounds with good to excellent yields in short times.Briefly, we have introduced tw...
Substituted pyrroles are an essential class of heterocyclic compounds. In this research, an efficient and eco-friendly method has been developed for the synthesis of pyrrole derivatives from the reaction of 2,5-hexanedione and primary amines. Magnetic nanoparticles supported on functionalized. 7-aminonaphthalene-1,3-disulfonic acid-functionalized. silica (Fe3O4@SiO2@Propyl–ANDSA) has been inves...
This work is focused on synthesis of SiO2- CNT hybrides via sol-gel method. Homogeneous distribution of carbon nanotubes within silicon matrix was obtained by mixing the functionalized carbon nanotube (CNTCOOH) with active silicic acid followed by titration to the solution of sodium silicate (Na2SiO3) under the average temperature condition of 80?C. Different ratios of multi-walled carbon nanot...
a mild and green method has been developed for the preparation of coumarins derivatives through the one-pot reactions. in our study,various phenols and ethyl acetoacetate compound in which we used silica-supported boron sulfonic acid [sio2/b(so4h)3] as a new, highly efficient and tri-functional inorganic brønsted acid catalyst were processed under solvent-free condition and thermal. the catalys...
In this study, bimodal mesoporous silica, i.e. UVM-7, was synthesized and functionalized withsulfonic acid and characterized using XRD, nitrogen physisorption, SEM, TEM and acid/basetitration. The results displayed that bimodal mesopore structure was firmly formed and acidicfunctional groups were grafted on the surface of the UVM-7. The concentration of the acidicfunctional groups was determine...
In this work preparation of sulfonic acid functionalized magnetite encapsulated zirconia (Fe3O4@ZrO2-SO3H) has been reported. Structural, chemical, and magnetic properties of the magnetically supported catalyst have also been investigated by Fourier transform infrared (FT-IR) spectroscopy, wide angle X-ray diffraction spectroscopy (WXRD), thermal gravimetric analysis (TGA), energy dispersive X-...
A suitable methodology of synthesis of coumarin derivatives by Pechmann reaction over heterogeneous solid acid catalysts in a free solvent media under microwave irradiation is described. Resorcinol, phenol and ethyl acetoacetate were selected as model reactants in the Pechmann condensation. The catalytic activity of several materials-Amberlyst-15, zeolite β and sulfonic acid functionalized hybr...
Post-grafting methodologies were used to prepare aryl-organosulfonic acid functionalized silica nanoparticles (SO3H-aryl-SiO2NPs) as highly active heterogeneous catalysts for catalytic esterification of free fatty acids (FFA) and levulinic (LA), aldol condensation furfural with 3-methylfuran, well known renewable feedstocks biodiesel fuel additives production. The chemical structural characteri...
An MCM-41-SO3H catalyst with 14 wt% S was successfully synthesized to be used in furfural production from xylose and hemicellulose a biphasic n-butanol/water system. The precursor MCM-41 the acid-functionalized were characterized by XRD, FTIR, TEM, N2 physisorption, ICP-MS, TPD-NH3, XPS. characterization results indicated that sulfonic process partially decreased ordered mesoporous structure in...
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