In this study, the nano-SiO2/hexamethylenetetramine as a new basic heterogeneous nanocatalyst was prepared and used for the synthesis of pyranopyrazole via the four-component reaction. Various aldehydes, hydrazine hydrate, ethyl acetoacetate and malononitrile were reacted at room temperature under solvent-free and grinding conditions. The morphology and structure of nano-cat...

an efficient, mild and environmentally friendly method was reported for the synthesis of an efficient, mild and environmentally friendly method was reported for the synthesis of pyranopyroles from aryl aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate in the presence of catalytic amounts of methyl imidazolium hydrogen sulfate ([hmim][hso4]) as an efficient catalyst. these synth...

The bifunctional pyrazolopyridine (2) and pyrano-pyrazole (3) derivatives were prepared by the reaction of 2-(2,4-dinitrophenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one (1) with p-methoxybenzaldehyde, malononitrile in the presence of ammonium acetate or piperidine, respectively. Compound 2 was used as the key intermediate to prepare the pyrazolo-pyrido-pyrimidine derivatives through its reaction ...

Unripe grape juice (verjuice) as a natural catalyst was successfully applied to perform the one-pot reaction of aryl aldehydes, malononitrile, hydrazine hydrate and ethyl acetoacetate to synthesize pyranopyrazole derivatives in aqueous ethanol at room temperature in excellent yields. Furthermore, unripe grape juice catalyzed one-pot synthesis of hexahydroquinoline-3-carboxamide derivatives by t...

Regioselective synthesis of highly functionalized pyranopyrazoles was achieved in excellent yield from phenyl pyrazolone, substituted aromatic aldehyde with nitroketene-N,S-acetal in the presence of indium trichloride as a versatile catalyst under reflux condition in ethanol-water mixture. All reactions preceeded within a short period of time with excellent purity. All of the synthesized compou...

In the current study, amorphous silica nanoparticles were easily extracted from rice husk ash. The target composite was synthesized by the direct incorporation of chloropropyl groups through the condensation of nanosilica and 3-chloropropyl trimethoxysilane and then grafting of 1,3,5-triazine-2,4,6-triamine (Melamine) onto the propyl groups by the simple nucleophilic substitution reaction (RHA@...