نتایج جستجو برای: Trisubstituted imidazoles
تعداد نتایج: 4534 فیلتر نتایج به سال:
[reaction: see text] A simple, high-yielding synthesis of 2,4,5-trisubstituted imidazoles from 1,2-diketones and aldehydes in the presence of NH(4)OAc is described. Under microwave irradiation, alkyl-, aryl-, and heteroaryl-substituted imidazoles are formed in yields ranging from 80 to 99%. Short syntheses of lepidiline B and trifenagrel illustrate the utility of this approach.
Substituted imidazoles are of interest because their useful biological activities. While several methods have been developed for the synthesis such compounds, some reported utilize corrosive or toxic catalysts. We report a bismuth (III) triflate catalyzed multicomponent 2,4,5-trisubstituted imidazoles. Bismuth compounds attractive from green chemistry perspective they remarkably non-toxic and n...
a general synthetic route to the synthesis of imidazoles has been developed using nano sbcl5/sio2 under solvent-free conditions. the multi-component reactions of aldehydes, benzil and ammonium acetate were carried out to afford some trisubstituted imidazole derivatives. this method provides several advantages like simple work-up, environmentally benign, and shorter reaction times along with hig...
A general synthetic route to the synthesis of imidazoles has been developed using nano SbCl5/SiO2 under solvent-free conditions. The multi-component reactions of aldehydes, benzil and ammonium acetate were carried out to afford some trisubstituted imidazole derivatives. This method provides several advantages like simple work-up, environmentally benign, and shorter reaction times along wi...
Disubstituted imidazoles were prepared by reacting appropriate phenylglyoxal with different aryl aldehydes in the presence of ammonium acetate. Trisubstituted imidazoles were prepared by reacting disubstituted imidazoles with chlorobenzene in the presence of catalytic amount of triethylamine (TEA). The synthesized compounds were characterized on the basis of IR, 1H-NMR and mass spectral data an...
a series of tri- and tetra- substituted imidazoles were synthesized from benzyl, aldehyde and ammonium acetate in the presence of zeolite as an ecofriendly reusable catalyst under microwave irradiation in the absence of solvent. the yields are high to excellent and the use of microwave irradiation reduces reaction times to few minute.
A simple highly versatile and efficient sonochemical synthesis of 1,2,4,5-tetrasubstituted and 2,4,5-trisubstituted imidazoles is achieved by condensation of 1,2-dicarbonyl compound, aldehyde, ammonium acetate and primary amine using antimony trichloride immobilized on silica gel (SiO2-OSbCl2) as a catalyst in ethanol at moderate temperature. Operational simplicity, practicability and applicabi...
A simple highly versatile and efficient sonochemical synthesis of 1,2,4,5-tetrasubstituted and 2,4,5-trisubstituted imidazoles is achieved by condensation of 1,2-dicarbonyl compound, aldehyde, ammonium acetate and primary amine using antimony trichloride immobilized on silica gel (SiO2-OSbCl2) as a catalyst in ethanol at moderate temperature. Operational simplicity, practicability and applicabi...
a simple highly versatile and efficient sonochemical synthesis of 1,2,4,5-tetrasubstituted and 2,4,5-trisubstituted imidazoles is achieved by condensation of 1,2-dicarbonyl compound, aldehyde, ammonium acetate and primary amine using antimony trichloride immobilized on silica gel (sio2-osbcl2) as a catalyst in ethanol at moderate temperature. operational simplicity, practicability and applicabi...
one-pot preparation of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles has been conducted in the presence of poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate, p(4vpbsa)hso4, as an efficient dual acidic catalyst under solvent-free conditions. reusability of the catalyst, easy work-up procedure, eco-friendly reaction conditions, short reaction times and high yields of th...
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