3,4-ِdihydropyrano[c]chromene derivatives were synthesized using sulfonic acid functionalized silica (sio2-pr-so3h) as a highly efficient heterogenous solid acid catalyst via one-pot three-component condensation of aromatic aldehydes with malononitrile and 4-hydroxycoumarin in excellent yields.

Polymer-electrolyte-membrane fuel cells (PEM-FCs) are considered as the most promising fuel cell technique for applications like automobiles or stationary power supplies. State-of-the-art separator materials in PEM-FCs are commonly sulfonic acid functionalized polymers, like the perfluorinated polymer Nafion. These materials show the required high proton conductivity only at high degree of hydr...

3,4-dihydropyrimidin-2(1H)-thiones were synthesized in the presence of Ag nanoparticle/melamine sulfonic acid (MSA) supported on silica gel. The reaction was carried out at 110 oC for 20 min under solvent free conditions. In all cases, the three component reaction proceeded smoothly to give the corresponding 3,4-dihydropyrimidin-2(1H)-thiones in moderate to good yield. We have found the best co...

3,4-dihydropyrimidin-2(1h)-thiones were synthesized in the presence of ag nanoparticle/melamine sulfonic acid (msa) supported on silica gel. the reaction was carried out at 110 oc for 20 min under solvent free conditions. in all cases, the three component reaction proceeded smoothly to give the corresponding 3,4-dihydropyrimidin-2(1h)-thiones in moderate to good yield. we have found the best co...

Recently, H2O2 is drawing growing interest in green chemistry 15 because it acts as direct and environmental benign oxidant in organic synthesis [2] and because its high cost limits the use for the production of bulk organic chemicals. The synthesis of hydrogen peroxide by direct reaction between H2 and O2 is a very attractive alternative to traditional anthraquinone 20 process. Direct synthesi...

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-...

IN THE TITLE COMPOUND [SYSTEMATIC NAME: 5-(5,7-dihydr-oxy-4-oxo-4H-chromen-yl)-2-hydroxy-benzene-sulfonic acid dihydrate], C(15)H(10)O(8)S·2H(2)O, the benzopyran-one ring is not coplanar with the phenyl ring, the dihedral angle between them being 41.35 (3)°. No H atom was placed on the sulphonic acid group because it was not possible to distinguish between the two S=O bonds and the S-O bond. In...

Heparin-based anticoagulants are drugs of choice in the therapy and prophylaxis of thromboembolic diseases. Idraparinux is a synthetic anticoagulant pentasaccharide based on the heparin antithrombin-binding domain. In the frame of our ongoing research aimed at the synthesis of sulfonic acid-containing heparinoid anticoagulants, we elaborated a modular pathway to obtain a series of idraparinux-a...