Ni2+ supported on hydroxyapatite-core@shell γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp-Ni2+) was found to be a useful catalyst for the synthesis of benzimidazole derivatives from o-phenylenediamine and aldehydes under solvent and solvent-free conditions at 80 °C. This reaction affords the corresponding benzimidazole derivatives compared with the classical reactions this method consistently gives a high...

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...

the use of methanesulfonic acid as a brønsted acid for direct ortho-acylation of phenols and naphthols proves to be a convenient, more general and direct route to various hydroxyaryl ketones. the route is regioselective, leading to ortho c-acylated products in satisfactory to high yields in most cases. the solvent free reactions described below exhibited environmentally benign in terms of faste...

a condensation of various isatins with indole derivatives has been carried out in the presence of 1,3-dibromo-5,5-dimethylhydantoin (dbdmh) as catalyst at 50 °c in ethanol in order to form 3,3-bis(indolyl) oxindoles. the products were obtained within 20-90 min by 70-96% yields. the efficacy of the procedure has been confirmed by catalyzing the condensation reaction of pyrrole which was used as ...

1,1-diacetates(acylals) were prepared by direct condensation of various aldehydes with acetic anhydride using dipyridine cobalt chloride (copy2cl2) as an efficient and green catalyst under solvent-free conditions at room temperature. the important features of this catalyst method are that the catalyst is solid, stable at high temperatures, soluble in water, stable in air, immiscible in common o...

pure azo schiff bases were readily and conveniently accessible in high yields by mixing of the reagents either as aqueous slurry, or by grinding at room temperature. this method, unlike a classical method, needs neither harsh conditions nor organic solvents. the satisfactory results were obtained with excellent yields, short reaction time, and operational simplicity in the experimental procedur...

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...

background & aim: essential oils are isolated from different sections of plants such as flowers, seeds, leaves, stems and roots. essential oils are applied extensively in producing of perfumes, cosmetics, foods, beverages and confectioneries and as ingredients of disinfectants and insecticides. experimental: essential oil are obtained by several isolation methods, such as hydrodistillation ...

Ketenimines and azadienes are transient intermediates in organic chemistry especially in elimination-addition processes and in the formation of heterocyclic systems. These compounds play a considerable role as intermediates in the synthesis of heterocyclic ring systems. In this present research synthesis of novel ketenimines and azadienes via multicomponent reactions (MCRs...

In this research, (Carboxy-3-oxopropylamino)-3-propylsilylcellulose (COPAPSC) as an organocatalyst, has been synthesized by grafting of succinic anhydride on the NH2-modified cellulose (cellulose functionalized with 3- aminopropyltriethoxysilane). The –CO2H group-functionalized cellulose (COPAPSC) is used as a catalyst for the synthesis of coumarin derivatives from the reaction of phenolic subs...