phospho sulfonic acid (psa) synthesized as an environmentally safe and efficient solid acid catalyst, and it used for the synthesis of several 2-disubstituted benzimidazoles, 2-substituted benzoxazoles, and 2-substituted quinoxalines in ethanol as a green solvent at ambient temperature is described. (i) a very simple, green and efficient procedure for the synthesis of benzimidazole and also benz...

A simple and mild one-pot three-component reaction for the preparation 1,4-dihydropyridines has been developed from various aldehyde substrates, 1,3-dicarbonyl compounds (dimedone) and ammonium acetate (Hantzsch method) in the presence of a catalytic amount of phospho sulfonic acid (PSA) as an efficient and heterogeneous solid acid in EtOH at room temperature. Preparation of PSA is straightforw...

a simple and mild one-pot three-component reaction for the preparation 1,4-dihydropyridines has been developed from various aldehyde substrates, 1,3-dicarbonyl compounds (dimedone) and ammonium acetate (hantzsch method) in the presence of a catalytic amount of phospho sulfonic acid (psa) as an efficient and heterogeneous solid acid in etoh at room temperature. preparation of psa is straightforw...

A simple and mild one-pot three-component reaction for the preparation 1,4-dihydropyridines has been developed from various aldehyde substrates, 1,3-dicarbonyl compounds (dimedone) and ammonium acetate (Hantzsch method) in the presence of a catalytic amount of phospho sulfonic acid (PSA) as an efficient and heterogeneous solid acid in EtOH at room temperature. Preparation of PSA is straightforw...

Silica boron sulfonic acid [SiO2–B(OSO3H)3] as an inexpensive, reusable, and Lewis and Brønsted acid catalyst was successfully synthesized, and used for the one-pot three-components synthesis of biologically active substituted Hantzsch 1,4-dihydropyridine derivatives  in the absence of solvent at 90ºC. Silica boron sulfonic acid is attractive and efficient, because it plays in two role as a Lew...

Phospho sulfonic acid (PSA) synthesized as an environmentally safe and efficient solid acid catalyst, and it used for the synthesis of several 2-disubstituted benzimidazoles, 2-substituted benzoxazoles, and 2-substituted quinoxalines in ethanol as a green solvent at ambient temperature is described. (i) A very simple, green and efficient procedure for the synthesis of benzimidazole and also benz...

sulfonic acid-based precursors (sap) play an important role in tailoring mesoporous silica’s and convert them to a solid acid catalyst with a bronsted-type nature. these kinds of solid acids contribute to sustainable and green chemistry by their heterogeneous, recyclable, and high efficiency features. therefore, knowing the properties and reactivity of saps can guide us to manufacture a sulfona...

a mild and green method has been developed for the preparation of coumarins derivatives through the one-pot reactions. in our study,various phenols and ethyl acetoacetate compound in which we used silica-supported boron sulfonic acid [sio2/b(so4h)3] as a new, highly efficient and tri-functional inorganic brønsted acid catalyst were processed under solvent-free condition and thermal. the catalys...

Two highly efficient protocols for the production of bis-coumarins under solvent-free conditions have been introduced. The reaction of 4-hydroxycoumarin (2 eq.) with arylaldehydes (1 eq.) using phthalimide-N-sulfonic acid (PhtSA) or isatin-N-sulfonic acid (IsSA), as solid-acid catalysts, afforded the mentioned compounds with good to excellent yields in short times.Briefly, we have introduced tw...

Inflammatory bowel disease is associated with inducible nitric oxide synthase (iNOS) expression, oxidative and nitrosative stress, and leukocyte infiltration in the colon. Here, we investigate the effects of the selective iNOS-inhibitor (S)-2-amino-(1-iminoethylamino)-5-thiopentanoic acid (GW274150) on the development of experimental colitis induced by dinitrobenzene sulfonic acid. When compare...