Thiamine hydrochloride (Vitamin-B1) has been utilized as an effective biodegradable catalyst for the one pot synthesis of polyhydroquinoline derivatives via four component reaction of dimedone, aldehyde, ethylacetoacetate and ammonium acetate in ethanol under mild conditions. The method presented here offers several advantages over reported procedures in terms of environmentally benign catalyti...

A Simple and efficient method for synthesis of tetrahydropyrimido[4,5-b]quinoline derivatives via three component reaction of aromatic aldehydes, dimedone and 6-amino uracil derivatives using a catalytic amount of sulfonic acid functionalized nanoporous silica (SBA-15-Pr-SO3H) is described. The advantages of this method are easy and clean work-up, high yield, mild reaction c...

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 SO3 H-containing solid acid namely SO3 H-functionalized phthalimide (SFP) was synthesized from phthalimide and chlorosulfonic acid, and identified by studying its FT-IR, 1 H and 13C NMR, Mass, XRD, TG and DTG spectra. Afterward, its catalytic activity was examined for the solvent-free condensation of dimedone (5,5-dimethyl-1,3-cyclohexanedione) (2 eq.) with arylaldehydes (1 eq.). The results ...

An efficient one pot multi component synthesis of 1, 4-Polyhydroquinoline derivatives through unsymmetrical Hantzsch reaction using lanthanum chloride heptahydrate (LaCl3.7H2O) from an aromatic aldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a nitrogen precursor in ethanol at room temperature is described. In the present work we report lanthanum chloride heptahydrate remarkably n...

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 rapid and efficient one-pot, four-component protocol towards the synthesis of polyhydroquinoline derivatives has been developed. The condensation of aldehyde, dimedone, ethyl acetoacetate and ammonium acetate in presence of stannous chloride was carried out under solvent free condition to synthesize a variety of polyhydroquinoline derivatives in good to excellent yields. Stannous chloride was...

An environmentally friendly, green, and highly efficient process for the synthesis of biologically and pharmacologically  4H-benzo[b]pyrans  and  3,4-dihydropyrano [c] chromenes  is  developed  by condensing cyclic aromatic aldehydes, malononitrile, and dimedone or 4‐hydroxycoumarin in the presence  of  lactic  acid  as  an  efficient  and  green  catalyst.  The corresponding  products  have  b...

Mesoporous silica LUS-1 (Laval University Silica) was successfully functionalized by propyl sulfonic acid and was used as a recyclable catalyst for the synthesis of acridine-1,8-diones via a pseudo four component reaction of aromatic aldehydes, dimedone and ammonium acetate (or anilines). The excellent yields, short reaction time, simple work-up procedure, and environmentally friendly condition...

A rapid and efficient one-pot, four-component protocol towards the synthesis of polyhydroquinoline derivatives has been developed. The condensation of aldehyde, dimedone, ethyl acetoacetate and ammonium acetate in presence of stannous chloride was carried out under solvent free condition to synthesize a variety of polyhydroquinoline derivatives in good to excellent yields. Stannous chloride was...