an efficient synthesis of polyhydroquinoline derivatives was reported via four-component coupling reactions of aldehydes, 1,3-dicarbonyl ketones (dimedone or 1,3-cyclohexanedione), ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of a catalytic amount of nanocrystalline tio2 under solvent free conditions. the reported method is mild, rapid and has the advantages su...

nano tio2 supported on sio2 (nano tio2@sio2) as a solid lewis acid, was described to be an effective and reusable catalyst for one-pot three-component reaction of benzil, aryl aldehydes and ammonium acetate for the synthesis 2-aryl-4,5-diphenyl-1h-imdazoles synthesis. to explore the high efficacy of the catalytic system the four-component cyclization of benzil, aryl aldehydes, ammonium acetate ...

in the present study, some new bis-imidazole derivatives have been prepared through four-components condensation of 2,6-bis (4-aminophenyl)-4-p-tolylpyridine, benzaldehyde derivatives, benzil and ammonium acetate in presence of acetic acid. the present methodology offers several advantages such as good yields, simple procedure, milder conditions and the possibility of introducing a variety of s...

in this study, the synthesis of 4 h -chromenes of biological activity via a multicomponent reaction of dimedone, aromatic aldehydes and malononitrile catalyzed by glutamic acid as a catalyst was investigated. the structural features of the synthesized compounds were characterized by melting point, ir and 1 h nmr analysis. the catalyst being reported here is cheap, safe to handle and the whole p...

mgo nanopartticels (np-mgo) in average size between 30—130 nm were prepared by sonochemistry method. some phenols have been converted to ortho-hydroxybezaldehyd by ortho-formylation using mgo nanoparticles and (ch2o)n in xylene and subsequently treated with aqueous nh2oh.hcl, affording the corresponding aldoxime in a one-pot procedure. moreover, this one-pot process, with two transformations, o...

a simple and green chemical procedure was reported for the synthesis of dihydropyrimidinones from various aldehydes, ethyl acetoacetate and urea or thiourea using  holmium chloride as catalyst. the reactions were performed under solvent free conditions with ultrasound irradiation as the energy source. the advantages of this protocol include the excellent yield, operational simplicity, short tim...

triphenyl phosphine(pph3), an efficient and reusable catalyst, catalysed the synthesis of 2-amino-3-cyano-6-methyl-4-aryl-4h-pyran-5-ethylcarboxylate derivatives by one-pot condensation of aromatic aldehydes, malononitrile and ethyl acetoacetate in etoh-h2o (1:1) at reflux conditions. the results show that aromatic aldehydes containing electron-donating groups or electron-withdrawing groups cou...

bifunctional acidic ionic liquids, having both h-imidazolium and -so3h groups as cation moieties (h-bfails) and cf3so3- as anion, were synthesized in high yields. these h-bfails showed significant hydrophilic properties, lower acidity and higher thermal stability relative to common ionic liquids, due to their unique structures. the (propyl or butyl-3-sulfonic) imidazolium trifluoromethane sulfo...