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Substituted quinoxaline derivatives are traditionally synthesized by co-condensation of various starting materials. Herein, we describe a novel environmentally benign in water synthetic route for the synthesis of structurally and electronically diverse ninety quinoxalines with readily available substituted o-phenylenediamine and 1,2-diketones using cheap and biodegradable itaconic acid as a mild acid promotor in 1 hours. The reaction is performed at room temperature, which proceeds through cyclo-condensation reaction followed by obtaining the aforesaid nitrogen-containing heterocyclic adducts without performing the column chromatography up to 96% total yields. The simplicity, high efficiency, and reusable of the catalyst merits this reaction condition as “green synthesis” which enables it to be useful in synthetic transformations upto gram scale level.

The application of 3,5-bis(trifluoromethyl)phenylammonium triflate (BFPAT) as a conven-ient new organocatalyst for the synthesis of quinoxaline derivatives is described. In the presence of BFPAT, one-pot synthesis of a wide variety of quinoxaline derivati

Here, the hydrothermal synthesis (HTS) of 2,3-diarylquinoxalines from 1,2-diketones and o-phenylendiamines (o-PDAs) was achieved. The synthesis is simple, fast, and generates high yields, without requiring any organic solvents, strong acids or toxic catalysts. Reaction times down to 90 % in all cases). Moreover, it was shown that HTS has high compatibility: (i) hydrochlorides, a standard commercial form of amines, could be used directly as combined amine source and acidic catalyst, and (ii) Boc-diprotected o-PDA could be directly employed as substrate that underwent HT deprotection. A systematic large-scale computational comparison of all reported syntheses of the presented quinoxalines from the same starting compounds showed that this method is more environmentally friendly and less toxic than all existing methods and revealed generic synthetic routes for improving reaction yields. Finally, the application of the synthesized compounds as fluorescent dyes for cell staining was explored.

A NaOH-mediated sustainable synthesis of functionalized quinoxalines is disclosed via redox condensation of o-nitroamines with diols and α-hydroxy ketones. Under optimized conditions, various o-nitroamines and alcohols are well tolerated to generate the desired products in 44-99% yields without transition metals and external redox additives.

Synthesis of a series of half-sandwich Ru(II) complexes (1-5) containing acylthiourea ligand is reported herein. All the Ru(II) complexes were well characterized by analytical and spectroscopic (UV-Vis, FT-IR, NMR and mass spectrometry) methods. Molecular structures of two (2 and 3) of the complexes were confirmed by single crystal X-ray diffraction, and the complexes adopted pseudo-octahedral geometry around Ru. Catalytic ability of the Ru complexes was evaluated in the synthesis of quinoxaline compounds from various 2-nitroaniline and hydroxy ketone derivatives via transfer hydrogenation approach. Active homogeneous catalyst was heterogenized by supporting it on graphene oxide, and the heterogeneous equivalent was characterized by Raman, XPS, TEM, SEM and ICP-OES techniques. Activity of the heterogeneous catalyst was tested, and it can be reused up to five cycles without any loss in activity.

Abstract: A novel –SO3H difunctionalized Bronsted acidic ionic liquid (BAIL) 1, 5-bis (butanesulphonic acid)-diazobicyclo [4,3,0] non-5-enium hydrogen sulphate [BBSA-DBN][HSO4] is introduced for efficient synthesis of quinoxalines vi

Aims and Objective: An efficient and practical procedure for the synthesis of heterocyclic compounds such as quinazolines, quinoxalines and bis(indolyl)methanes was developed using 3,5-bis(trifluoromethyl) phenyl ammonium hexafluorophosphate (BFPHP) as a novel organocatalyst. Materials and Methods: All of the obtained products are known compounds and identified by IR, 1HNMR, 13CNMR and melting points. Result: Various products were obtained in good to excellent yields under reaction conditions Conclusion: The BFPHP organocatalyst demonstrates a novel class of non-asymmetric organocatalysts, which has gained much attention in green chemistry.

An efficient, simple and eco-friendly procedure is reported in presence of heterogeneous Dowex 50W catalyst in aqueous medium under refluxing condition to produce quinoxaline derivatives. Catalyst has participated in condensation reaction between 1,2-diamines and various aromatic 1,2-diketones smoothly with excellent yield of the products in short reaction times. Dowex 50W was used more than five times in this reaction separately and showed an excellent recyclability throughout the reaction.(figure presented).

In this study, a novel acid-functionalized magnetic nanoparticles with high loaded multifunctional acidic groups was fabricated by anchoring water-soluble 5-sulfosalicylic acid onto the surface silica-modified Fe3O4. The magnetically recyclable Fe3O4@SiO2@5-SA (20?mg) showed excellent reactivity for greener synthesis of tetrahydrobenzo[b]pyrans via a three-component reaction of different aromatic aldehydes, malononitrile and dimedone in good to excellent yields (70–95percent) in pure water at short reaction times (40–150?min). The method shows eco-friendly synthesis of quinoxaline derivatives from direct condensation of substituted 1,2-diamine with various 1,2-dicarbonyl in ethanol at room temperature to afford the desired quinoxalines with good to excellent yields (60–97percent) at shorter reaction times (120–240?min). The morphology and magnetic properties of MNPs were studied with scanning electron microscopy, X-ray powder diffraction, Fourier translation infrared spectroscopy, vibrating sample magnetometer and thermogravimetric. The results showed that the Fe3O4@SiO2@5-SA catalyst is completely recoverable by an external magnet and retained catalytic activity after five recycles.

A concise method for the construction of heteroaryl-fused phenazines was developed via PIFA-BF3·Et2O-mediated oxidative coupling of di-heteroarylated quinoxalines for the first time. Synthesis of mono- and di-heteroarylation of quinoxaline was performed effectively using only LiTMP reagent under transition metal-free conditions and without the use of halogen-containing starting compounds. In addition, nonsymmetrical di-heteroarylated quinoxalines were synthesized through reheteroarylation of mono-heteroarylated quinoxalines in the same way. Oxidation of the saturated compounds formed after heteroarylation was easily accomplished with iodine. The UV-vis absorption and fluorescence features of some compounds were examined.

Three copper(I) complexes, [CuCl(L)(PPh3)2] [L = FL (1), BL (2) or TL (3)] were prepared from [(PPh3)2Cu(μ-Cl)2Cu(PPh3)] and N-carbamothioylfuran-2-carboxamide (FL), N-carbamothioylbenzamide (BL) or N-carbamothioylthiophene-2-carboxamide (TL) ligands in benzene and four-coordinated tetrahedral copper complexes were well characterized by various spectroscopic techniques (UV/Vis, FT-IR, 1H NMR, 13C NMR and 31P NMR). The molecular structure of the ligands (FL and BL) and complexes was established from single-crystal X-ray diffraction studies. Copper complexes have been shown to catalyse the one-pot synthesis of imines and quinoxalines. Heterogenized catalyst (4) was prepared by reacting more active complex 3 with polystyrene supported triphenylphosphane, and characterized by elemental analyses, and DRS-UV, FT-IR, ICP-OES, and solid-state NMR techniques. Catalytic activity of the complexes (3 and 4) was tested in the formation of imines from alcohols and amines, and quinoxalines from hydroxy ketones and diamines. Heterogeneity and reusability of catalyst 4 were evaluated, and the catalyst can be reused for four runs without any loss in activity.

A novel method for the synthesis of pyrazines and quinoxalines has been developed using α-hydroxyketones and 1,2-diamines in the presence of cross-linked poly(4-vinylpyridine)-stabilized Pd(0) nanoparticles, [P4-VP]-PdNPs. The catalyst was easily prepared and characterized using various techniques such as FT-IR and UV–Vis spectroscopy, AAS, TEM, FESEM, EDX analysis and XRD. The results confirm a good dispersion of palladium nanoparticles on the polymer support. The catalyst displayed good catalytic activity when applied to the synthesis of quinoxalines via condensation of α-hydroxyketones with 1,2-diamines. A few pyrazine derivatives and various quinoxalines are prepared via coupling reaction of α-hydroxyketones and 1,2-diamines in high–excellent yields (81–99%) with short reaction times. The quinoxalines products were characterized by FT-IR, 1H and 13C NMR spectroscopy, and the physical properties were compared to the literature values of known compounds. The advantages of the present method over conventional classical methods are rapid and very simple work-up, and the catalyst is reusable many times without a significant loss in its activity.

This is the first reported, unconventional, efficient strategy for the synthesis of quinoxaline from 2 to iodo benzoic acid and sodium azide in presence of organo Cu (II) catalyst. Herein, a very simple, versatile one pot multi-component protocol for the synthesis of biologically active compound, quinoxaline has been described via Schmidt reaction and the nucleophilic substitution reaction. The isolated compounds were characterized by 1H NMR, 13C NMR. Our reported organo catalyst was characterized by single crystal XRD, SEM.

CO2-assisted various symmetric and non-symmetric α-diketones have been synthesized directly from the corresponding aldehydes using transition metal-free catalysts. This method can even be applied to synthesize pharmaceuticals directly from aldehydes. The crucial role of CO2 has been investigated in detail and the mechanism is proposed on the basis of experiments and DFT calculations.

Conventional homogeneous and microporous heterogeneous catalysts for quinoxalines production from diamines and diketones usually suffer from difficult separation or harsh reaction conditions. Here, we demonstrate the production of various substituted quin

An efficient p-toluene sulfonic acid–catalyzed, one-pot, two-step oxidative system for cyclization of o-diaminobenzene with 1,2-diaryl-2-hydroxyethanone to quinoxalines was described. A nontoxic, readily available oxidant, dimethylsulfoxide (DMSO), was applied in this process. A broad range of substrates was applied to this method, and target compounds were obtained with good yields.

An efficient, simple, and green procedure for the synthesis of quinoxaline derivatives catalyzed by Fe3O4@SiO2-imid-PMAn nanoparticles at room temperature is described. This environmentally benign method provides several advantages such as mild reaction conditions, good to excellent yields, short reaction times, simple work-up and catalyst stability, easy preparation, heterogeneous nature and easy separation of the catalyst. Also, nanocatalyst can be easily recovered by a magnetic field and reused for the next reactions for at least 6 times without distinct deterioration in catalytic activity. SEM, BET, DLS and leaching of catalyst after each reaction cycle were investigated. Furthermore, antifungal activity of various derivatives against three phytopathogenic fungi (Alternaria alternata, Pyricularia oryzae, and Alternaria brassicae) was investigated.

The corrosion behavior of mild steel in 1 M H2SO4 was studied using 2,3-diphenylpyrazine (DP), 2,3-di(furan-2-yl)pyrazine (FP) and 2,3-di(furan-2-yl)quinoxaline (FQ) as inhibitors using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) methods were utilized for surface characterization. The results showed that the three inhibitors possess excellent inhibition effect toward mild steel corrosion. The inhibitor molecules are adsorbed on the mild steel surface, blocking the reactive sites available for acid attack. Adsorption of the inhibitor was found to obey Langmuir isotherm. Electronic structure calculations were used to study the inhibition efficiency of the inhibitor molecules on Fe (100) surface. The calculated results are in agreement with the experimental findings.

An efficient iodine-DMSO catalyzed system for the synthesis of quinoxaline derivatives was developed. The construction of this quinoxaline system went through a one-pot oxidation/cyclization process. The reaction afforded a variety of products in good to excellent yields. This methodology has potential applications in the synthesis of biologically and medicinally relevant compounds.

A straightforward one-pot preparation of library of quinoxalines from 2-nitroanilines under entirely metal-free conditions is described. Initial reduction of nitroaniline with hydrazine hydrate is efficiently catalyzed by graphene oxide (GO) or reduced graphene oxide (rGO), and further one-pot tandem reactions with 1,2-dicarbonyl compounds or with α-hydroxy ketones afford quinoxalines in excellent yields. The catalyst is recovered, characterized, and found to be recyclable for consecutive four runs examined with appreciable conversions.

Protic ionic liquids (PILs), which are easily produced through the combination of a Bronsted acid and Bronsted base, such as [Mim]Ac and 1,4-diazabicyclo[ 2.2.2]octane (DABCO):AcOH:H2O (1:1:3), were found to be lucid, tunable tool for synthesis

A simple, greener and highly efficient method for the synthesis of functionalized quinoxalines has been developed employing l-proline as a catalyst in water. To the best of our knowledge this transformation is achieved for the first time using an organic catalyst. A small library of quinoxaline-sulphonamide conjugates have been synthesized using this protocol. The newly synthesized conjugates have been tested for their cytotoxicity and antimicrobial activity against several bacterial strains including one fungal strain. The majority of the compounds have exhibited significant cytotoxicity as well as antimicrobial activity. Compounds 5a, 5b and 5d were found to be promising with respect to both cytotoxicity and antimicrobial activity. This journal is

In this study, Yb immobilized NaY zeolite catalyst (Yb/NaY) was obtained by a hydrothermal method and characterized by XRD, BET, FT-IR, ICP-AES, and NH3-TPD. The catalyst displayed good catalytic activity when applied to the synthesis of quinoxalines via condensation of α-hydroxyketones with 1,2-diamines, and could be reused several times without any loss of catalytic activity.

In this work, we report the novel successful preparation of the Keggin-type Cs(CTA)2PW12O40 (CTA = cetyltrimethylammonium cation) nanostructure by a microemulsion method. The microemulsion system included the cationic surfactant CTAB, 1-butanol as co-surfactant, isooctane as oil phase, and an aqueous solution containing CsNO3. The Cs(CTA)2PW12O40 nanostructure was formed by the addition of an aqueous solution of phosphotungstic acid to the microemulsion solution. Characterization of the resultant nanostructure was done using FT-IR spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, and CHN elemental analysis. The product was found to be a star-shaped nanostructure composed of some nanorods whose diameter and length are about 100 nm and 500 nm, respectively. The prepared nanostructure was used as a recoverable catalyst for the synthesis of quinoxaline derivatives by the condensation of 1,2-diamines with 1,2-dicarbonyl compounds, which afforded the products in good to high yields in short reaction times.

A simple, inexpensive, environmentally friendly and efficient route for the rapid and efficient synthesis of quinoxaline derivatives using pentafluorophenylammonium triflate (PFPAT) as a catalyst is described. Various quinoxaline derivatives were synthesi

A polyvinylpolypyrrolidone supported triflic acid was shown to be useful as a recyclable heterogeneous catalyst for the rapid and efficient synthesis of quinoxaline derivatives in good-to-excellent yields. The catalyst is easily prepared, air-stable, reus

ZrO2 nanocatalyst has been obtained successfully using novel and safe agents through a simple and safe sol-gel method (polymerizing-complexing) and characterized by XRD, FT-IR, Raman spectroscopies and transmission electron microscopy (TEM). Raman spectroscopies and XRD results indicated only formation of monoclinic zirconia. TEM images revealed spherical nanoparticles with 20-40 nm diameter range. The spectral and analysis data confirmed the effectiveness of the method for preparation of monoclinic zirconia by preventing grain growth or agglomeration of particles. The nanostructured ZrO2 exhibited high efficiency in catalyzing condensation of various 1,2-diamine and 1,2-dicarbonyl compounds for the synthesis of heterocyclic compounds. The recovery of the title heterogeneous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from the bulk one.

A facile and simple catalyst-free protocol has been developed for the condensation of 1,2-diketones with aromatic 1,2-diamines in polyethylene glycol (PEG), providing quinoxaline derivatives in good yields. The important features of the methodology are broad substrates scope, simple workup, catalyst free, environmentally benign, and no requirement for metal catalysts. It is noteworthy that the cyclization reaction of 1,2-diketones with aliphatic 1,2-diamines is also conducted smoothly to afford pyrazines in good yields under the standard conditions. In addition, PEG could be recovered easily and was reused without evident loss in activity

Crystalline nanobelts of α-MoO3 have been obtained successfully using novel and safe agents through a simple and safe sol-gel method (polymerizing-complexing) and characterized by XRD, FT-IR, Raman spectroscopies, high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and the temperature programmed desorption (TPD) of ammonia. An orthorhombic lattice system for nano-MoO3 was established. The HRTEM images showed that the nanobelt morphology of α-MoO3 mostly ranged from 20-70 nm in width and 200-400 nm in length. The ammonia TPD profile demonstrated strong acidic sites. The spectral and analysis data confirmed the effectiveness of the method for the preparation of α-MoO3 nanobelts by prevention of grain growth or agglomeration of the particles. The nanostructured MoO3 exhibited a high efficiency in catalyzing the condensation reaction of various 1,2-diamine and carbonyl compounds for synthesis of heterocyclic compounds. The recovery of the title heterogenous nanocatalyst was easy and efficient and its catalytic activity was strikingly different from the bulk material.

A zirconium(IV) complex of a bidentate Schiff base (ZrL2Cl 2) has been synthesized by the reaction of (z)-N-benzylidene-2- hydroxypropane-1-amine (HL) and ZrCl4. Spectroscopic data and elemental analyses are consistent with a monomeric complex with a ligand:Zr ratio of 2:1. The catalytic activity of ZrL2Cl2 has been investigated for the efficient synthesis of a wide variety of quinoxaline derivatives under mild conditions. The employment of ethanol as an environmentally benign solvent in this high yield method, along with high turnover numbers and reusability of the catalyst providing ready scalability, makes it appropriate for practical applications.

The scope and limitations of surfactants as catalysts for the synthesis of quinoxalines using microreactors made of the surfactants in water has been assessed. The catalytic potential followed the order: non-ionic surfactants > anionic surfactants > Bronsted acid surfactants > cationic surfactants. The non-ionic surfactant, Tween 40, is the most effective catalyst affording excellent yields within a short reaction time at room temperature and is compatible with different variations of the 1,2-diketones and 1,2-diamines. The reaction medium (spent water) containing the catalyst, as well as the catalyst itself (recovered Tween 40) can be reused for five consecutive reactions. The better catalytic efficiency of the surfactant (Tween 40) compared to the various Lewis/Bronsted acids, as well as the surfactant combined Lewis acid, suggests that surfactants, which generate microreactor assemblies at the interface, are better suited as catalytic aids to promote organic reactions in water. The inferior results obtained in organic solvents, which provide a homogeneous reaction mixture compared to those obtained in water, indicate the specific role of water. This has been depicted as a synergistic dual activation through the hydrogen bond mediated formation of supramolecular assemblies involving a water dimer and the reactants. The catalytic assistance of the surfactant could be ascribed to the ability of the surfactant molecule to undergo hydrophobic and hydrogen bond forming interactions with water and the reactants in orienting the reactants at the water interface and encapsulating inside the microreactors to facilitate the cyclocondensation. The Royal Society of Chemistry 2013.

A new simple approach using environmentally benign, cheap, and easily recyclable graphite as a heterogeneous catalyst for the synthesis of quinoxalines is described. A library of pharmacologically interesting diphenylquinoxalines is prepared by the double condensation of substituted benzils, phenanthrene-9,10-dione, and benzoin with aromatic diamines in 71-93% yields at room temperature in ethanol. Aliphatic diamines gave corresponding dihydropyrazines from substituted benzils in 72-92% yields.

A simple and efficient protocol has been developed for the synthesis of biologically relevant 2-substituted benzimidazoles and quinoxalines using magnetically separable manganese ferrite (MnFe2O4) nanopowder for the first time as a reusable heterogeneous catalyst at room temperature under aerobic conditions. MnFe2O4 nanoparticles were prepared by a simple sol-gel method using starch as a bio-polymeric matrix, and characterized by XRD, TEM, EDAX and VSM analyses. The Royal Society of Chemistry 2013.

A one-pot efficient and facile protocol for the direct synthesis of quinoxaline derivatives via tandem N-heterocyclic carbene (NHC)-catalyzed umpolung of aldehydes/oxidation of the benzoins to benzils/condensation of benzils with benzene-1,2-diamines has been developed. Georg Thieme Verlag Stuttgart New York.

An efficient and convenient synthesis of quinoxalines from easily available aldehydes was performed as a one-pot procedure in good to excellent yields under metal-free conditions, via sequential benzoin condensation, aerobic formation of benzils and condensation of the latter with 1,2-diaminobenzenes.

One-step conversion including intramolecular hydrogen bond decomposition, aerobic oxidation, and condensation from α-hydroxyketones and 1,2-diamines into quinoxalines is reported using FeCl3 and morpholine as cocatalysts. Taylor & Francis Group, LLC.

The aerobic oxidation of α-hydroxy ketones into α-diketones catalyzed by CaO is compared with the same reaction catalyzed by other metal oxides. The catalytic activities of the various metal oxides were proportional to their surface basicities. The direct conversion of α-hydroxy ketones into quinoxalines via CaO-catalyzed aerobic oxidation followed by in situ reaction with 1,2-diaminoaromatics is also achieved. Various types of quinoxalines were synthesized in the presence of the CaO catalyst and molecular oxygen. It was also found that the CaO catalyst was reusable without any loss of its catalytic activity.

The condensation reaction of 1,2-diketones and o-phenylenediamines was investigated in the presence of nano-sized mesoporous silica (MCM-41) supported 12-tungstophosphoric acid (TPA) as solid acid catalyst. Nano-sized MCM-41 was synthesized and the catalysts with different loading amounts of TPA (5-15 wt.%) were prepared and characterized by XRD, FT-IR and SEM techniques. The results confirm good dispersion of TPA on the solid support. The catalyst is reusable many times without loss in its activity.

Hexafluoroisopropanol (HFIP) is explored as an effective medium for the synthesis of quinoxaline derivatives in high yields at room temperature. The solvent (HFIP) can be readily separated from reaction products and recovered in excellent purity for direc

An efficient and facile method has been developed for the condensation of 1,2-diamines with-hydroxyketones in polyethylene glycol (PEG) to quinoxalines and pyrazines with good yields in the presence of silica sulfuric acid (SSA). The important features of the methodology are simple operations, environmentally friendliness, and no requirement for metal catalysts. Additionally, the catalyst system (SSA/PEG) could be recovered easily and reused.

An efficient and facile synthesis of quinoxaline derivatives in excellent isolated yields by the condensation of 1,2-diamines and 1,2-diketones on grinding under solvent-free conditions at ambient temperature has been developed. The important features of this method are that it is reasonably fast, very clean, high yielding, simple workup, and environmentally benign.

Alumina as a cheap, heterogeneous and reusable catalyst can provide environmentally friendly alternatives for synthesis of quinoxaline derivatives via condensation of 1,2-diamines and 1,2-dicarbonyl compounds under solvent-free conditions. The products could be separated simply from catalyst by filtration and the catalyst could be recycled and reused for several times without noticeably decreasing in catalytic activity.

A variety of biologically important quinoxaline derivatives has been efficiently synthesized in excellent yields under extremely mild conditions using PEG-600 and water. This inexpensive, non-toxic, ecofriendly and readily available system efficiently condensed several aromatic as well as aliphatic 1,2-diketones with aromatic and aliphatic 1,2-diamines to afford the products in excellent yield. Polyethylene glycol (PEG) can be recovered and recycled. Indian Academy of Sciences.

The room temperature ionic liquid 1-n-butyl-3-methylimmidazolium tetrafluoroborate ([bmim]BF4) was used to promote the synthesis of quinoxaline derivatives under grinding condition. The yields were ranged in 86.0-95.1%. It was shown that the proposed method is fast, efficient and environmentally benign.

TiO2 nanoparticles were synthesized and characterized by SEM and XRD techniques. The TiO2 nanoparticles were employed as a recyclable, inexpensive and efficient catalyst for the synthesis of substituted quinoxalines in high to excellent yields and in relatively short duration.

A straightforward, efficient and more sustainable catalyst-free method has been developed for the synthesis of quinoxaline, benzoxazole, and benzimidazole ring system in glycerol to achieve yields that were comparable to or better than, those in conventional media. It is noteworthy that the reaction was exclusively carried out in glycerol-water system, rendering the methodology highly valuable from both environment and economic points of view.

A library of quinoxaline derivatives were prepared to target non-structural protein 1 of influenza A (NS1A) as a means to develop anti-influenza drug leads. An in vitro fluorescence polarization assay demonstrated that these compounds disrupted the dsRNA-NS1A interaction to varying extents. Changes of substituent at positions 2, 3 and 6 on the quinoxaline ring led to variance in responses. The most active compounds (35 and 44) had IC50 values in the range of low micromolar concentration without exhibiting significant dsRNA intercalation. Compound 44 was able to inhibit influenza A/Udorn/72 virus growth.

The aerobic oxidation of alcohols and synthesis of quinoxalines was developed in a one-pot biomimetic approach using recyclable ruthenium on charcoal and randomly methylated β-cyclodextrin in water under neutral conditions overcoming many of the drawbacks in the earlier methodologies. The catalytic system can be recycled up to five cycles without loss of activity. Georg Thieme Verlag Stuttgart New York.

Amberlyst-15/H2O has been used as an efficient and environmentally friendly catalytic system for the synthesis of quinoxalines. The present methodology offers several advantages, such as excellent yields, short reaction time, and simple workup. Copyright Taylor & Francis Group, LLC.

A novel, environmentally friendly procedure has been developed for the synthesis of quinoxaline derivatives in the presence of magnetic Fe 3O4 nanoparticles. The reaction between 1,2-diamines and 1,2-dicarbonyl compounds was carried out in water to afford quinoxaline derivatives in high yield. The catalyst can be recovered by the use of an external magnet and reused for five cycles with almost consistent activity. CSIRO 2010.