a highly efficient, simple and clean solvent-free protocol for the synthesis of polyhydroquinolines is described. the one-pot multi-component condensation reaction between arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters and ammonium acetate in the presence of catalytic amount of (2.5 mol%) melamine trisulfonic acid (mtsa) as a recyclable, green and attractive sulfonic ...

melamine trisulfonic acid (mtsa) as an efficient heterogeneous catalyst has been used for the one-pot preparation of triazolo[1,2-a]indazole-1,3,8-trione and 2h-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives by the three-component condensation reaction of urazoles or phthalhydrazide, dimedone or 1,3-cyclohexanedione, and aldehydes under solvent-free conditions in good to excellent yields ...

A simple, mild and efficient method for the regioselective nitration of various aromatic compounds usingpoly(4-vinylpyridinium nitrate) (P4VPyN) in the presence of melamine trisulfonic acid (MTSA), is reported.This method provides several advantages such as good selectiveity between ortho and para positions ofaromatic compounds, clean procedure, simple work-up, short reaction times, solvent-fre...

A novel catalytic synthesis of 3,3'-(arylmethylene)-bis-(4-hydroxy-2H-chromene-2-one) derivatives from a tandem condensation reaction of 4-hydroxycoumarin and aromatic aldehydes has been developed. The reaction occurs in water in the presence of Melamine trisulfonic acid as catalyst to give the corresponding products in good to high yields. This green approach has several advantages such as sho...

a simple, mild and efficient method for the regioselective nitration of various aromatic compounds usingpoly(4-vinylpyridinium nitrate) (p4vpyn) in the presence of melamine trisulfonic acid (mtsa), is reported.this method provides several advantages such as good selectiveity between ortho and para positions ofaromatic compounds, clean procedure, simple work-up, short reaction times, solvent-fre...

A highly efficient, simple and clean solvent-free protocol for the synthesis of polyhydroquinolines is described. The one-pot multi-component condensation reaction between arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters and ammonium acetate in the presence of catalytic amount of (2.5 mol%) melamine trisulfonic acid (MTSA) as a recyclable, green and attractive sulfonic ...

a novel catalytic synthesis of 3,3'-(arylmethylene)-bis-(4-hydroxy-2h-chromene-2-one) derivatives from a tandem condensation reaction of 4-hydroxycoumarin and aromatic aldehydes has been developed. the reaction occurs in water in the presence of melamine trisulfonic acid as catalyst to give the corresponding products in good to high yields. this green approach has several advantages such as sho...

A novel catalytic synthesis of 3,3'-(arylmethylene)-bis-(4-hydroxy-2H-chromene-2-one) derivatives from a tandem condensation reaction of 4-hydroxycoumarin and aromatic aldehydes has been developed. The reaction occurs in water in the presence of Melamine trisulfonic acid as catalyst to give the corresponding products in good to high yields. This green approach has several advantages such as sho...

TiO2 nanoparticles/melamine Tri sulfonic acid (MTSA) supported on silica gel as an efficient catalytic system for simple, one pot, solvent-free and environmentally benign process for synthesis of dihydropyrimidines via Biginelli reaction at 110 °C is described. It was found that the catalyst is reusable and exhibited remarkable activity. The catalyst can be easily separated and reused several t...

TiO2 nanoparticles/melamine Tri sulfonic acid (MTSA) supported on silica gel as an efficient catalytic system for simple, one pot, solvent-free and environmentally benign process for synthesis of dihydropyrimidines via Biginelli reaction at 110 °C is described. It was found that the catalyst is reusable and exhibited remarkable activity. The catalyst can be easily separated and reused several t...