Search

A novel Bi-Mg-O composite nano-catalyst was prepared by using Bi(NO3)3 and nano-MgO. Prepared catalyst was characterized using x-ray diffraction (XRD) analysis, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) technique which confirms its nano-crystalline nature and composition. The synthesized novel catalyst Bi-Mg-O was found to be competent catalyst for the synthesis of spirooxindole derivatives by multicomponent reaction of isatin, dimedone, malononitrile and 4H-pyran derivatives by reaction of dimedone, aryl aldehydes and malononitrile using ethanol as solvent at room temperature. The nanocatalyst proved to be recyclable as it is recycled and recovered for three runs without notable loss in catalytic activity. All synthesized derivatives were obtained in exemplary yields. Novel recyclable nanocatalyst, good yields of products, and benign reaction conditions are the noteworthy aspects of the present protocol. [ABSTRACT FROM AUTHOR]

A novel robust acidic ionic liquid dihydrogen 4,4′-trimethylenedipiperidine phosphate was synthesised from 4, 4′-trimethylenedipiperidine and phosphoric acid. The prepared catalyst was characterized by FTIR, 1H-NMR, 13C NMR and mass spectroscopy. The synthesized novel catalyst was found to be competent for synthesis of pyranopyrazole derivatives through one-pot multicomponent condensation of diverse aryl aldehydes with malononitrile, ethyl acetoacetate and hydrazine hydrate in the presence of a catalytic amount of dihydrogen 4,4′-trimethylenedipiperidine phosphate [H2-TMDP][HPO4] as an efficient and inexpensive catalyst at room temperature. The novel catalyst proved to be rapid and efficient for synthesis of pyranopyrazole derivatives attributing to excellent yields of 86–92% within 12–16 min. Merits of this meticulously designed protocol are the use of novel ionic liquid, easy work-up process, good to excellent yields, short reaction time and purification without column chromatography. [ABSTRACT FROM AUTHOR]

New three-component reaction was developed via one-pot strategy for the synthesis of functionalized 3,3′-disubstituted oxindoles and spirooxindole through the reaction among isatin, malononitrile, and acetone/indole/nitromethane/acetylacetone/dimedone in ethanol as solvent without base. It was observed that all the mixed ligand transition metal complexes with triphenylphosphine worked as the efficient catalysts. The present methodology agreements several advantages, including simplicity of the preparation and handling of the catalyst, simple and easy work-up, short reaction times, high yields of the products. [ABSTRACT FROM AUTHOR]

Herein we have developed solvent extraction method for thorium(IV) with 0.15 M N-n decylaniline in xylene from 0.5 M H2SO4. Physicochemical parameters like acid concentration, amine concentration, equilibrium time, phase ratio, diluent, loading capacity to name a few were optimized for the quantitative extraction of thorium(IV). The back-extraction of thorium(IV) from organic phase was done with 0.1 M nitric acid and determined complexometrically. To extend the utility of this method, binary and ternary mixture separation, extraction of thorium(IV) from monazite sand and gas mantle are also investigated. [ABSTRACT FROM AUTHOR]

CuO nanobelts and nanoparticles were selectively synthesized using specific precipitating agents such as NaOH and Na2CO3 , respectively. Catalytic activity of these nanocrystals is explored by synthesizing a series of benzopyran derivatives by reaction of dimedone, aryl aldehydes and malononitrile in a water:ethanol (70:30) mixture. The developed protocol is endowed with appealing features such as a recyclable catalyst, high yields and shorter reaction time. [ABSTRACT FROM AUTHOR]

Liquid-liquid extraction of Au(III) from aqueous sodium malonate medium using 2-octylaminopyridine (2-OAP) as an extractant in xylene was achieved. The current work explored the influence of several experimental parameters such as pH, weak acid concentration, extractant concentration, equilibrium time, stripping agents, and aqueous:organic volume ratio on the extraction of Au(III). The experimental results showed that the Au(III) was quantitatively extracted to about 99.5% by 0.05 M 2-OAP in 0.05 M malonate at 5.0 pH. Ammonia solution was used to strip the gold-loaded organic phase and about 99.5% of Au(III) was reversibly extracted into the aqueous phase. Gold(III) was extracted into the organic phase via formation of ion-pair complex [2-OAPH+ .Au (C3H2O4)2-]. The stoichiometry of the extracted species was 1:2:1 (metal: acid: extractant) determined by slope analysis. The method affords the binary, ternary mixture separation as well as separation of Au(III) from synthetic mixtures and alloys. The method is applicable for the determination and separation of gold from ayurvedic samples and recovery of gold from e-wastes. A reproduction of the method was checked by finding relative standard deviation for n = 5, which was 0.29%, and the limit of detection was 1.08 μg/mL. [ABSTRACT FROM AUTHOR]

A proficient and meticulously designed diasterioselective, multicomponent, one-pot synthesis of densely substituted piperidine derivatives has been elaborated using polystyrene sulfonic acid catalyst via tandem reactions of 1,3-dicarbonyl compounds, aromatic aldehydes and various amines. Shorter reaction times, high yields and a polymer-supported inexpensive catalyst are the noteworthy aspects of the scaffold. Graphical Abstract: [ABSTRACT FROM AUTHOR]

A series of novel 18-crown-6 ether functionalized bis-benzimidazole derivatives ( 3a- g) have been synthesized by reacting various substituted ortho-phenylene diamines and pyridine diamines with 4,4′-diformyl dibenzo-18-crown-6 ether ( 1). The required starting material 4,4′-diformyl dibenzo-18-crown-6 ether ( 1) was prepared by Duff formylation method. All synthesized novel molecules have been identified on the basis of infrared (IR), H nuclear magnetic resonance (NMR), C NMR, mass spectroscopy (MS), and elemental analyses. The title compounds ( 3a- g) were tested for antifungal activity against Aspergillus niger, Trichothecium sp., Rhizopus sp., and Sclerotium rolfsii fungi species using agar well diffusion method, showing mild to good results. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The quest to develop an environmentally friendly, sustainable protocol for immensely bioactive spirooxindole derivatives has encouraged to explore oxalic acid dihydrate: proline low transition temperature mixture as a new designer solvent for the said synthesis at room temperature. It has been successfully applied for the three component reaction of isatin, malononitrile or ethyl cyanoacetate and 1,3-dicarbonyl compounds for the first time. Moderate to good yield of the products, shorter reaction time, energy efficiency, chromatography-free purification process, recyclability and high atom economy are the captivating feature of this protocol which will find applications in multi-component, diversity-oriented synthesis. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An innovatively designed novel crown ether functionalized imidazolium-based reusable acidic ionic liquid [crown ether MIm] [HSO] has been efficiently implemented for the synthesis of pyrazole derivatives using various substituted enaminones, hydrazine hydrate and phenyl hydrazine under solvent-free conditions. Structural novelty and task efficiency of the catalyst, high yields of desired products, greener approach attributing high atom economy and solvent-free conditions render this protocol suitable to cope with the current demand in contemporary organic chemistry. The inventive idea of utilizing crown ether functionalized ionic liquid as a catalyst was for the first time demonstrated in this protocol. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A novel series of benzo crown ether (dibenzo 18-crown-6 ether, benzo 18-crown-6 ether, and benzo 15-crown-5 ether) functionalized enamines derivatives from amino benzo crown ether (4-amino dibenzo 18-crown-6 ether, 4-amino benzo 18-crown-6 ether, 4-amino benzo 15-crown-5 ether) and substituted 3-(dimethylamino)-1-phenylprop-2-en-1-one compounds have been synthesized. All the synthesized compounds were characterized by infrared,1H NMR,13C NMR, distortionless enhancement polarization transfer, and mass and elemental analysis techniques. The cation recognition property for benzo crown ether enamine8awas studied by absorption and fluorescence spectroscopy. [ABSTRACT FROM PUBLISHER]

Polystyrene-supported sulfonic acid has been found to be an efficient catalyst for the one-pot, three-component synthesis of 2 H-indazolo[2,1- b]phthalazinetriones in greener solvent glycerol. Use of greener solvent glycerol along with a polymer-supported, low toxic, and inexpensive catalyst renders the method eco-friendly. High yields, simple product isolation procedure, and fluorescent and electroluminescent natures of the products are the noteworthy aspects of this protocol. [ABSTRACT FROM AUTHOR]

(±)-Camphor-10-sulfonic acid is used for the synthesis of triazolo[1,2-a]indazole-triones and spiro triazolo[1,2-a]indazole-tetraones by condensation reaction of dimedone, urazole and aromatic aldehydes or isatin. The noteworthy aspects of this new method are high yields, high atom efficiency, use of non-toxic solvent, mild conditions, simple workup and synthesis of complex molecules using an eco-friendly, inexpensive catalyst. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstracts: A novel, highly efficient and recyclable Brønsted acidic ionic liquid ([CMIM][CFCOO]) has been successfully implemented for the synthesis of acridinediones in aqueous media. Recyclability of novel catalyst, high yields, use of environmentally benign aqueous media as solvent, simple product isolation, high atom economy and sidestep to column chromatography are the noteworthy features of this protocol. This protocol is competent for producing wide library of acridinediones in good to excellent yields. Furthermore, molecular structure and relative stereochemistry of 4c and 4s derivatives were confirmed by single-crystal X-ray diffraction. Graphical Abstract: [InlineMediaObject not available: see fulltext.] [ABSTRACT FROM AUTHOR]