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A new catalytic application of tetraethylammonium L-prolinate for the facile and cleaner synthesis of 4,4′-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s is developed. This amino acid-based ionic liquid could be recycled up to five runs, and a negligible reduction of catalytic activity was detected within the experimental error. A variety of substituted 4,4′-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s were obtained in good to high yields under eco-friendly conditions. Tetraethylammonium L-prolinate is easy to prepare, as well as it shows moderate thermal stability and good solubility in water. This work revealed that this amino acid-based ionic liquid, containing L-prolinate anion, can catalyze the tandem Knoevenagel-Michael condensation reaction due to hydrogen bond donor and Lewis base moieties. The current methodology has other advantages, including (a) wide substrate-scope, (b) relatively short reaction times, (c) the use of a nontoxic, biocompatible, biodegradable and metal-free ionic liquid, and (d) simple workup procedure.

Pyrans have been extensively explored in both academic organizations and pharmaceutical industries owing to their biological characteristics, including anticancer activity.1,2 Among the pyrans, pyr...

Dual solvent-catalytic activity of 1,1′-butylenebis(3-sulfo-3H-imidazol-1-ium) chloride was studied for the synthesis of coumarins under mild conditions. In addition, the catalytic efficiency of so...

4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO3H) has been successfully synthetized and fully characterized by FT-IR and high-resolution NMR spectroscopy (1H, 13C). The “plausible” alterna...

4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO3H) has been synthesized and completely characterized by FT-IR, one-dimensional NMR spectroscopy (1H, 13C). The “plausible” alternative structures of ...

The condensation of 5-amino-1H-benzotriazole and 5,5-dimethylcyclohenxane-1,3-dione with aryl aldehydes was efficiently promoted in the presence of poly(N-vinylimidazole) in ethanol at reflux condi...

An environmentally benign, simple, and efficient process has been developed for biodiesel production from waste olive oil in the presence of a catalytic amount of TiO2 nanoparticles at 120°C with a conversion of 91.2% within 4 h. The present method affords nontoxic and noncorrosive medium, high yield of biodiesel, clean reaction, and simple experimental and isolation procedures. The catalyst can be recycled by simple filtration and reused without any significant reduction in its activity.

The synergistic effect of TiO2 nanotubes as an efficient nano-catalyst and sonication as a green energy source was investigated for the synthesis of azo-linked xanthene derivatives via the eco-frie...

A multi-step catalyst-free synthesis of azo compounds by using n-butyl nitrite as a diazotization reagent and p-toluene sulfonic acid as a mild acidic agent in ethanol/water mixed solvent was inves...

A series of new azo-linked xanthene derivatives was synthesized via the eco-friendly multi-component condensation of azo-linked salicylaldehyde derivatives and dimedone under ultrasound irradiation...

An environmentally benign, simple, and efficient procedure has been developed for the one-pot multicomponent synthesis of pyrazolo[3,4-d]pyrimidine-6-one derivatives by the reaction of the variety ...

This study was carried out to produce biodiesel from olive oil waste by transesterification reaction. Several important reaction variables (the weight ratio of oil to methanol, the temperature, and reaction time) were evaluated to obtain a high quality of biodiesel fuel that meets authentic standards. Solar energy was applied for the transesterification reaction and electricity generated by photovoltaic panels was used to power a motor for mixing the reaction solution.

Succinimide-N-sulfonic acid as an efficient Bronsted acid catalyzed the synthesis of pyrano[4,3-b]pyrans by using solar energy as a green source of energy under solvent-free conditions. This method has the advantages of high yield, short reaction time, and clean and simple methodology. The catalyst could be recycled without significant loss of activity.

In this article, the synthesis of xanthene derivatives catalyzed by poly(4-vinylpyridi-nium) perchlorate is presented under grinding and solvent-free conditions. This methodology consistently has the advantages of excellent yields and the fast rate of reactions. The catalyst can be recovered by simple filtration and used for several times without a significant leaching and loss of catalytic activity.