Reactions of N-isocyaniminotriphenylphosphorane with a cyclic ketone in the presence of ferrocene carboxylic acid proceeded smoothly at room temperature and in neutral conditions to afford ferrocene-containing 1,3,4-oxadiazole derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed. The structures of the products were deduced from their IR, 1HNMR, and 13CNMR spectra. The method offers a mild, simple, and efficient route for the preparation oreaction of N-isocyaniminotriphenylphosphorane with cyclic ketones in the presence of ferrocene carboxylic acid proceeded smoothly at room temperature and in neutral conditions to afford ferrocene-containing 1,3,4-oxadiazole derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed. The structures of the products were deduced from their IR, 1HNMR, and 13CNMR spectra. f sterically congested ferrocene-containing 1,3,4-oxadiazole derivatives from cyclic ketones, N-isocyaniminotriphenylphosphorane (Ph3PNNC) and ferrocene carboxylic acid. Its ease of workup, high yields and fairy mild reaction conditions make it a useful addition to modern synthetic methodologies.
Oil spills have the most important environmental impact in oceans and seas. In this article, oil absorption, which was explored from Sardar-e-Jangal oilfield in Caspian Sea by exfoliated graphite (EG), was investigated. Graphite was exfoliated through the reaction of graphite-CrO3 intercalation compounds with hydrogen peroxide. The obtained absorbent was characterized by Brunauer-Emmett-Teller (BET), Fourier transform infrared spectrometer (FT-IR), X-ray Diffraction (XRD), RAMAN spectroscopy, scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS). Absorption capacity was investigated by response surface methodology (RSM) using design expert data analysis. EG absorbed oil sample from aqueous solution to a great extent as it was due to increasing total pore volume in its structure in comparison to the simple graphite. RSM model fitting and its validation was discussed. Identified parameters (weight of absorbent and oil) were investigated by RSM using Perturbation diagram, contour and 3D surface response plots and the maximum absorption ratio was 27.6 gram (g) oil/gram (g) absorbent. The finding presented herein indicated that EG was successfully used in oil removal from seawater due to its easy synthesis, low cost and high sorption performance.
In this research work, a proficient method has been developed for the preparation of novel N-((2-chloroquinolin-3-yl) methylene)-4-methylbenzenamine derivatives from 2-chloroquinoline-3-carbaldehyde derivatives and p-toluidine in ethanol as solvent and using catalytic amount of acetic acid under reflux conditions to obtain desired products in good yields. The identification of all the synthesized compounds was confirmed by melting point, FT-IR, H NMR, and C NMR. Also, in the present work, all the synthesized compounds were evaluated for their molecular docking as anti-HIV-1 reverse transcriptase inhibitors using GOLD 5.2. software. The results of molecular docking showed that all the compounds established ‘π–π’ interactions with side chain of amino acid.
In this paper we report the synthesis and characterization of two new mononuclear Cd(II) macrocyclic Schiff base complexes [CdL23pydfp(NO3)], (1), [CdL33pydfp(NO3)], (2). [1+ 1] cyclocondensation of L-23py = N-(2-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminoethane, L-33py = N-(3-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminopropane and 2,6-diformyl-4-methylphenol, dfp, in the presence of Cd(NO3)(2)center dot 4H(2)O in equimolar ratios gave two new macrocylclic complexes. Resulting complexes were characterized by NMR, IR, mass spectroscopy and elemental analysis. Spectroscopy results show nitrogen and oxygen atoms of macrocyclic ligand with N4O donor set, one nitrate molecule (with two donor oxygen atoms) is coordinated to the Cd(II) center in each complex. So, the cadmium center is seven coordinated.
Four liquid crystal compounds of the form, 2-Sec-butyl-4-[(4-x-phenyl) diazenyl) phenyl-4-(octadecyloxy] benzoate symbolized as I18a, I18b, I18c and I18d were prepared in which the substituent (X) was taken CH3O-, CH3-, Br- and -NO2 respectively. Characterization of prepared compounds is done using FT-IR, H-1-NMR, Mass Spectroscopy and Elemental Analysis. Their mesophase behavior was investigated by Differential Scanning Calorimetry (DSC). Their antioxidant efficiency for Egyptian lubricating base oil was tested. The oxidation processes were monitored using the change in the Total Acid Number (TAN). The obtained results showed that the efficiency of these compounds was ranked as follows I18d > I18c > I18b > I18a.
Multiwalled Carbon Nanotube (MWCNT) reinforced silica aerogel was synthesized in a very simple and cost effective sol -gel method. The process was followed by ambient pressure drying, and then the aerogel material was characterized by XRD, BET, SEM, EDX and FT-IR. 2.3 x 10(-3) wt% MWCNTs were successfully incorporated in sodium silicate based silica aerogel. This metal-free nanocomposite catalyzed a four component organic reaction among 4-hydroxy coumarin, benzaldehyde, phenyl hydrazine, and ethyl acetoacetate for synthesizing medicinally important benzylpyrazolyl coumarin at room temperature. The MWCNT/silica aerogel composite material having easy accessible active sites and high catalytic activity was easily recovered and reused. The aerogel composite when impregnated with ceria offered very efficient and selective reaction methodology.
The objective of this study is to design a simple, fast, sensitive and single-use electrode with the simultaneous capability of preconcentration and measuring for application in a three-electrode voltammetry system to identify and measure the heavy metal cadmium. The design process of this sensor consists of several stages. The polyurethane foam and multi-walled carbon nanotube nanoparticles were functionalized and the new nanocomposite was synthesized. Besides, with the help of an organic solvent, established on the pencil graphite electrode, it was covered with hollow fiber. In this work, for the first time, the organic solvent was employed instead of ionic liquid. The designed sensor was used to detect and measure heavy metal cadmium through differential pulse voltammetry technique, whose appearance of a sharp peak at -0.82 V indicates thepresence of cadmium. It was found that the presence of air molecules as the analyte carrier (between hollow fiber cavities and in fixed nanocomposite on the graphite) instead of organic solvents or ionic liquids was desirable. All the synthesis stages of nanocomposite were analyzed by infrared spectroscopy. Finally, the nanocomposite morphology was obtained with a Scanning Electron Microscope. A calibration curve was drawn and a linear response with a range of 2.39 to 47.6 mu M was plotted. The LOD of the designed sensor was 0.399 mu M for cadmium. The mentioned sensor was used to recognize the measurement of analyte in real biological samples of urine, nail, and wastewater of the laboratory.
Via the one-pot condensation reaction of ethyl acetoacetate, aromatic aldehydes, 2,4-dinitrophenylhydrazine, and beta-naphthol, new pyrazolone derivatives were synthesized in the presence of three Bronsted acid catalysts. These Bronsted acid catalysts are silica sulfuric acid (SSA), tetra-n-butyl ammonium hydrogen sulfate (TBAHSO(4)) and [2,2'-Bipyridine]-1,1'-diium tricyanomethanide {[2,2'-BPyH][C(CN)(3)](2)}. Each of the combinations has its own characteristics. SSA is a heterogeneous catalyst. TBAHSO(4) is a phase transfer catalyst and {[2,2'-BPyH][C(CN)(3)](2)} is an ionic liquid. We compared the obtained results of the catalysts. In most cases, the results were comparable. But, sometimes TBAHSO(4) and {[2,2'-BPyH][C(CN)(3)](2)} give the better results to the SSA in terms of reaction time and yields. Even though, isolation of SSA from products was easier than the separation of two other catalysts.
Two highly efficient protocols for the production of bis-coumarins under solvent-free conditions have been introduced. The reaction of 4-hydroxycoumarin (2 eq.) with arylaldehydes (1 eq.) using phthalimide-N-sulfonic acid (PhtSA) or isatin-N-sulfonic acid (IsSA), as solid-acid catalysts, afforded the mentioned compounds with good to excellent yields in short times.
An efficient and convenient synthesis of novel tetrahydrobenzo[c]acridin-8(7H)-one derivatives is described using the electrogenerated anion of acetonitriles as the base in the presence of tetrabutylammonium fluoride as an effective supporting electrolyte in a one-pot, three-component condensation of aromatic aldehyde, dimedone and 1-naphthyl amine. The reaction carried out in an undivided cell containing an iron cathode and a graphite anode under a constant current density of 5 mA/cm(2) (I=20 mA, electrode surface=5 cm(2)) in CH3CN at room temperature was found to be optimum for the electrochemically induced chain process and resulted in the highest yield.
In the present paper, informatics-aided quantitative structure activity relationship (QSAR) models using genetic algorithm-partial least square (GA-PLS), genetic algorithm-Kernel partial least square (KPLS), and Levenberg-Marquardt artificial neural network (LM ANN) approach were constructed to access the antimalarial activity (pIC(50)) of 2,5-diaminobenzophenone derivatives. Comparison of errors and correlation coefficients was obtained by the models as it illustrated that the LM ANN approach works with a high correlation coefficient and low prediction error. This model was applied to the prediction of pIC(50) values of 2,5-diaminobenzophenone derivatives.
In this protocol, 3-(2-carboxybenzoyl)-1-methyl-1H-imidazol-3-ium chloride [Cbmim]Cl and sulfonic acid functionalized pyridinium chloride [pyridine-SO3H]Cl as a new, reusable, and green Bronsted acidic ionic liquid (BAIL) catalyst were synthesized and successfully used for the one-pot ring-opening of epoxide with sodium azide (NaN3) in water at room temperature. Epoxides undergo ring-opening readily with NaN3 in the presence of [Cbmim]Cl and [pyridine-SO3H]Cl to afford the corresponding beta-azido alcohols as attractive and interesting materials in drug design and pharmaceutics compounds in high yield with good regioselective under mild reaction conditions.
A one pot green three-component coupling reaction of aldehyde, phenylacetylene, and amine derivatives in the presence of copper (II)-thioamide combination as a novel and efficient heterogeneous catalyst under solvent-free conditions is reported. The catalyst displayed high activity and afforded the corresponding propargylamines in good to high yields. The key to this procedure was the generation of Cu (I) required for the A(3) coupling reaction, which was achieved by in situ reduction of Cu (II) using thiobenzanilide as reduction agent and ligand. The structure of the products was confirmed by H-1 NMR, C-13 NMR and EI-MS and comparison with authentic samples prepared by reported methods.
The aim of this study was to synthesize a new oxetan-phenyltetrahydropyridazine-3,6-dione derivative (compound 6) using different techniques. The first method was achieved by the preparation of a phenylhydrazine derivative (2) using three-components system (3,17-aldol-estradiol, phenylhydrazine, 5-hexyn-3-ol) in the presence of Copper(II). Then, 2 was reacted with tert-butyldimethylsilyl chloride to form the compound 3 (trimethylbutan-silyloxy-steroid-hydrazine). Following, a pyridazine derivative (4) was prepared by the reaction of 3 with succinic acid using boric as catalyst. The compound 4 was reacted with hydrofluoric acid to form the tetrahydropyridazine-3,6-dione (5). Finally, the preparation of 6 was carried out by the reaction of 5 with CopperII. Spectroscopy analyses NMR was used to confirm the chemical structure of compounds. In conclusion, a facile method to synthesize an oxetan-phenyltetrahydropyridazine-3,6-dione is reported.
A protocol for the synthesis of 1,4-dihydropyridines (Hantzsch type-products) was developed through a three-component condensation of aldehydes, ss-dicarbonyl compound and ammonium acetate in the presence of nano Al2O3/KF as catalyst. This reaction was carried out under different conditions including i) solvent-free conditions, ii) refluxing in different solvents. However, the reactions proceed in refluxing ethanol (10 mL). The reported protocol has the advantages of consistently excellent yields and short reaction times. The catalyst could be recovered easily.
Annulated pyrano[2,3-d] pyrimidine/pyrano[2,3-d] uracil derivatives were synthesized using aromatic aldehydes, active methylene compounds and barbituric acid in presence of dibutylamine (DBA) catalyst in ethanol as solvent. The different substituents on phenyl ring in the fused pyrano uracil skeleton showed productive influence on its antimicrobial activity against some gram positive and gram negative bacteria like Pseudomonas aureus, E. coli, Staphylococcus aureus, Klebsiella pneumonia and Bacillus cereus. Antibacterial screening revealed that the presence of heteroaryl, cyano and amino groups on uracil skeleton increases its penetrating power on bacterial cell wall and product becomes more biologically energetic. The antimicrobial-activity results showed some definite and interesting facts about the structure activity relationship (SAR) of synthesized molecules.
In the present work, the reaction between disodium salt of 1,3-dihydroxybenzene (in situ formation) and propargyl bromide was carried out in a solid-liquid biphasic phase transferring catalytic system at 50 degrees C. Higher selectivity of the bis-derivative (1,3-bis( prop-2-ynyloxy) benzene) was obtained under solid-liquid PTC condion. The conversion of propargyl bromide to more than 99% was achieved in the presence of tetra-n-butylammonium bromide (TBAB) as PTC catalyst. From the experimental evidence, no mono-derivative was observed. Experiments were conducted to increase the conversion of propargyl bromide such as, stirring speed, various PTCs, temperature, various solvents and amount of TBAB loading. All the experiments were conducted to obey pseudo-first order rate law. Apparent activation energy was also determined from the Arrhenius plot.
Fe2V4O13 is prepared and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV-diffuse reflectance spectroscopy (UV-DRS), high resolution scanning electron microscopy (HR-SEM) using energy dispersive X-ray spectroscopy (EDX) analysis. The hetero-Fenton catalyst can be used to mineralize Methyl Orange (MO) under UV-A light. The mineralization rate is influenced by hydrogen peroxide (H2O2) concentration, pH, and catalyst loading. The reusability of Fe2V4O13 is analyzed by five successive runs. At the maximum, 95% of degradation is observed in all five cycles. Therefore, the Fe2V4O13 catalyst is found to be reusable. The mineralization is confirmed by chemical oxygen demand (COD) measurements. Mechanism of the heterophoto-Fenton process is also proposed.
Four new azo-dyes, 3-phenyl azopentane-2,4-dion (LA), 3-(4-nitro phenyl azo)-pentane-2,4-dion (LP), 3-(2-nitro phenyl azo)-pentane-2,4-dion (LO) and 4-(1-acetyle-2-oxo-propyl azo)-benzene sulfonate sodium (LS), were synthesized from, aniline, 4-nitroaniline, 2-nitroaniline and sulfanilic acid with acetylacetone, respectively. Reaction of these new dyes with acetate salts of copper(II), nickel(II) and cobalt(II) in molar ratios of 1:2 were carried out to produce azo metal (II) complexes with the general stoichiometry; CuL2, CoL2 and NiL3 in complexes. Structure of azo dyes was characterized using FT-IR,1H NMR,13C NMR, UV-Visible and also the corresponding metal (II) complex were characterized by FT IR, UV-Visible and CHN and XRD analysis techniques. Elemental analysis and spectral data indicated that the dye as a ligand with two teeth, N and O, acts as a bidentate ligand. Differences in absorption maxima of azo ligands compared to those corresponding complexes were also studied. Also, in this work, singular value decomposition (SVD) as a chemometric method was used to determine the Cu(II), Co(II) and Ni(II) complexes with the mentioned ligands in methanol by UV-Vis spectrophotometry. SVD method confirmed the formation of CuL2, CoL2 and NiL3 complexes.
Various antibacterial fluoroquinolone compounds were prepared by the direct amination of 7-halo-6- fluoroquinolone-3-carboxylic acids with variety of piperazine derivatives and (4aR, 7aR)-octahydro-1H-pyrrolo[3,4-b] pyridine using Zirconia Sulfuric Acid (ZrSA) nanoparticle, as a catalyst in refluxing water. The results showed that ZrSA exhibited high catalytic activity towards the synthesis of fluoroquinolone derivatives, with the desired products being formed in high yields. Furthermore, the catalyst was recyclable and could be reused at least three times without any discernible loss in its catalytic activity. Overall, this new catalytic method for the synthesis of fluoroquinolone derivatives provides rapid access to the desired compounds in refluxing water following a simple work-up procedure, and avoids the use of harmful organic solvents. This method, therefore, represents a significant improvement over the methods currently available for the synthesis of fluoroquinolone derivatives.
