نتایج جستجو برای: hantzsch method
تعداد نتایج: 1630350 فیلتر نتایج به سال:
The four-component Hantzsch condensation reaction of dimedone, ethyl acetoacetate, ammonium acetate, and various aromatic and aliphatic aldehydes in the presence of catalytic amount of a magnetic nanoparticle-supported tribromide, as a green catalyst, under solvent‐free conditions at 80 °C affords functionalized 5-oxo-hexahydroquinolines in good to excellent yields. The magnetic Fe3O...
An efficient and environmental-friendly synthetic route to 1,8-dioxodecahydroacridines derivatives have been developed via multi-component one-pot Hantzsch reaction of various aldehydes and ammonium acetate with 2 equivalents dimedone in the presence of Phosphorus pentoxide supported on aluminaas catalyst under solvent-free conditions. The present approach offersseveral advantages such as short...
A protocol for the isothiourea-catalysed transfer hydrogenation of ?,?-unsaturated para-nitrophenyl esters using Hantzsch ester has been developed. Good to excellent yields are observed aryl bearing electron-withdrawing ?-substituents. The products can either be isolated directly in moderate (7 examples, 16–98%) or converted corresponding methyl (2 68–70% yield) benzyl amides 44–88% after situ ...
Sulfated titania nanoparticles (SO42-/TiO2 NPs) were synthesized using titanium tetraisopropoxide (TTIP) by the sol-gel method. The structure and morphology of the prepared nanocatalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) methods as well as Fourier transform infrared (FT-IR) and energy dispersive X-ray (EDX) spectr...
Two new ligand systems related to the previously described DOTTADs have been generated in a simple one step reaction. The first, trans-DOTTADs, were formed by Vilsmeier formylation (followed by cyclisation and N-demethylation) of 2,6-dimethyl-3,5-pyrazine-dicarboxylic acid, to give the novel bis-pyridinopyrazine dialdehyde ligands. The corresponding pyrazine diester, reacted similarly to an int...
sulfonic acid functionalized sba-15 (sba-pr-so3h) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. sba-pr-so3h was proved to be an efficient heterogeneous ...
abstract part one: the electrode oxidation potentials of a series of eighteen n-hydroxy compounds in aqueous solution were calculated based on a proper thermodynamic cycle. the dft method at the level of b3lyp-6-31g(d,p) was used to calculate the gas-phase free energy differences ,and the polarizable continuum model (pcm) was applied to describe the solvent and its interaction with n-hydroxy ...
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