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...

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 ...

This work described an efficient Pseudo four-component synthesis of (10E)-N-benzylidene-2-phenylH-imidazo[1,2-a]pyridin-3-amine derivatives from 2-aminopyridin, malononitrile and arylaldehydes in the presence of NaOH under solvent-free and conventional heating condition in good to excellent yields. A wide range of aromatic aldehydes would easily undergo condensations with 2-aminopyridin and mal...

The synthesis of pharmaceutically and biologically active 2-amino-4H-chromenes was described using TiO2/nanoclinoptilolite (TiO2/NCP) as an efficient nanocatalyst under solvent-free condition. The TiO2/NCP was fabricated through modification of NCP with HDTMA, then the surface modified NCP was impregnated with titanium tetrachloride solution. Finally, the materi...

o-xylylenebis (triphenylphosphonium peroxymonosulfate) (1) was easily prepared from an aqueous solution of oxone and o-xylylenebis- (triphenylphosphonium bromide). this compound (1) is a useful and selective reagent for conversion of oximes, semicarbazones and phenylhydrazones to the corresponding carbonyl compounds. the reaction was carried out under solvent-free conditions and in the presence...

as benzimidazole ring is an important pharmacophore in modern drug discovery and benzimidazoles are very important intermediates in organic reactions, the preparation of benzimidazoles has gained considerable attention in recent years. here, a comparative study on the synthesis of benzimidazoles from aromatic, aliphatic and heterocyclic carboxylic acid, benzonitrile and o-phenylenediamine under...

cellulose bonded n-propyl diethylene tetra sulfamic acid (cbpdetsa) was successfully applied as a green and recyclable acidic catalyst for the synthesis of tetrahydrobenzo [a] xanthene-11-one as an important class of potentially bioactive compounds. the products are obtained by the coupling of 2-naphtol , cyclohexadione and aldehyde derivatives in good to high yields (70- 92%) under solvent-fre...