Physical chemistry
Pouya Karimi; Mahmoud Sanchooli
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 173-179
Abstract
Stability of the π-π stacking interactions in the Ben||N-substituted-coronene complexes was studied using the computational quantum chemistry methods (where Ben is benzene and || denotes π-π stacking interaction, and N-substituted-coronene is coronene molecule which substituted with different ...
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Stability of the π-π stacking interactions in the Ben||N-substituted-coronene complexes was studied using the computational quantum chemistry methods (where Ben is benzene and || denotes π-π stacking interaction, and N-substituted-coronene is coronene molecule which substituted with different number of N atoms). The results reveal simultaneous effects of structure and number of Heteroatom on the π-π stacking interactions with N-substituted-coronenes. Changing the number of Heteroatom N in N-substituted-coronenes and substitution of 8N-coronene with electron-withdrawing or electron-donating X groups alter the electron charge density at rings of this molecule and leads to different binding energies in the Ben||X-8N-substituted-coronene complexes. Results indicate that electron-withdrawing groups lead to higher π–π stacking binding energies compared to electron-donating ones in the Ben||X-8N-substituted-coronene complexes.
Analytical chemistry
Roghiyeh Pourghobadi; Mohammad Reza Baezzat
Abstract
The present study examines a new dopamine sensor based on Alumina nanoparticles modified carbon paste electrode (Al2O3NPsCPE). Moreover, the present study focuses on the electrochemical act of the Al2O3NPsCPE for the detection of dopamine by cyclic voltammetry (CV) and differential pulse voltammetry ...
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The present study examines a new dopamine sensor based on Alumina nanoparticles modified carbon paste electrode (Al2O3NPsCPE). Moreover, the present study focuses on the electrochemical act of the Al2O3NPsCPE for the detection of dopamine by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). There is also a focus on the specification of the prepared modified electrode by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM), and there is a discussion on the influence of some experimental variables such as carbon paste composition, laboring solution pH, scan rate and possible interferences. The present study obtained a well-defined redox peak of dopamine (DA) on the Nano- Alumina/CPE at Epa=173mV and Epc=112mV, respectively. The obtained response of the sensor was linear under the optimal conditions of the catalytic peak current, in the range of 8.0-330.0 µM, and the detection limit was 2.1 µM (S/N=3) for dopamine. The proposed sensor exhibited a high sensitivity, an excellent reproducibility, good selectivity, and it was successfully used in the determination of dopamine injection samples.
Organic chemistry
Nader Noroozi Pesyan; Ali Gharib; Azam Monfared
Abstract
A convenient route for cyanation and bromination of some electron-rich aromatics (anisole, 1,3-dimethoxybenzene, 1,4-dimethoxybenzene, 1,3,5-trimethoxybenzene and β-naphthol) by BrCN in the presence of aluminum trichloride (AlCl3), as catalyst, by grinding method under solvent-free conditions at ...
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A convenient route for cyanation and bromination of some electron-rich aromatics (anisole, 1,3-dimethoxybenzene, 1,4-dimethoxybenzene, 1,3,5-trimethoxybenzene and β-naphthol) by BrCN in the presence of aluminum trichloride (AlCl3), as catalyst, by grinding method under solvent-free conditions at room temperature to 60 °C was described in good yield. The structures of all obtained products were characterized by FT-IR, 1H NMR, 13C NMR, and Mass spectrometry techniques. Anisole and 4-cyanobenzonitrile afforded both cyanated and brominated products. 1,3-Dimethoxybenzene yielded to two types of the cyanated products. 1,4-Dimethoxybenzene has done some unusual coupling reactions via new Beckmann-type rearrangement. No bromination of 1,4-dimethoxybenzene was observed under the same conditions. 1,3,5-Trimethoxybenzene and β-naphthol obtained both cyanated and brominated products which were analyzed by HPLC technique.
Organic chemistry
Hamid Saeidian; Farzaneh Moradnia
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 252-261
Abstract
An efficient construction of 2-(N-arylamino)benzaldehydes and N-aryl-3,10-dihydroacridin-1(2H)-one derivatives starting from 2- hydroxybenzaldehydes has been developed. The synthesis of N-aryl-3,10-dihydroacridin-1(2H)-ones is based on the Knoevenagel condensation of dimedone to various 2-(N-arylamino)benzaldehydes, ...
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An efficient construction of 2-(N-arylamino)benzaldehydes and N-aryl-3,10-dihydroacridin-1(2H)-one derivatives starting from 2- hydroxybenzaldehydes has been developed. The synthesis of N-aryl-3,10-dihydroacridin-1(2H)-ones is based on the Knoevenagel condensation of dimedone to various 2-(N-arylamino)benzaldehydes, followed by an intramolecular enamination in the presence of 20 mol% of nanocrystalline ZnO. Moderate to high yields, operation simplicity, and cheap starting materials are the key features of the present method. The structures of the products were confirmed by 1H and 13C NMR spectroscopy and mass spectrometry (EI). Probable mechanisms for the present reactions to account for the formation of 2-(N-arylamino)benzaldehydes 3a-h and N-aryl-3,10-dihydroacridin-1(2H)-one derivatives 4a-h are also reported.
Analytical chemistry
Burla Sunitha Seshamamba; Peruri Veera Satyanarayana; Chandra Sekharan
Volume 2, Issue 4, pp. 236-325, Serial No. 5 , October 2014, , Pages 255-268
Abstract
Two simple visible spectrophotometric methods are developed and validated for the quantification of modafinil using 1,2-naphthoquinone-4-sulphonic acid (NQS method) and 2,4-dinitrophenol (DNP method) as analytical reagents. The NQS method involves the reaction of modafinil with 1,2-naphthoquinone-4-sulphonate ...
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Two simple visible spectrophotometric methods are developed and validated for the quantification of modafinil using 1,2-naphthoquinone-4-sulphonic acid (NQS method) and 2,4-dinitrophenol (DNP method) as analytical reagents. The NQS method involves the reaction of modafinil with 1,2-naphthoquinone-4-sulphonate in alkaline medium at room conditions to form a yellow colored product exhibiting maximum absorption at 430 nm. DNP method is based on the proton transfer from 2,4-dinitrophenol to modafinil at room conditions and then we have the formation of yellow colored ion-pair complex exhibiting maximum absorption at 475 nm. Different variables affecting the reaction were studied and optimized. Under the optimized experimental conditions, Beer's law is obeyed in the concentration ranges of 10-100 and 8-60 μg/mL with the detection of limit values of 0.486 and 0.258 μg/mL for NQS method and DNP method, respectively The molar absorptivity and Sandell's sensitivity for both of the methods are reported. The methods were validated in terms of accuracy, precision and robustness. The results were satisfactory. The proposed methods were effectively applied to the analysis of the modafinil in their tablet formulations. The recoveries were 99.92% and 99.96% with RSD and 0.863% and 0.722% for NQS and DNS methods, respectively. The assay was not interfered by common excipients.
Organic chemistry
Bagher Mohammadi; Mansoor Shafieey; Hamed Kazemi
Volume 3, Issue 4, pp. 283-387, Serial No. 9 , October 2015, , Pages 302-309
Abstract
This work described an efficient Pseudo four-component synthesis of (10E)-N-benzylidene-2-phenylH-imidazo[1,2-a]pyridin-3-amine derivatives from 2-aminopyridin, malononitrile and arylaldehydes in the presence of NaOH under solvent-free and conventional heating condition in good to excellent yields. A ...
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This work described an efficient Pseudo four-component synthesis of (10E)-N-benzylidene-2-phenylH-imidazo[1,2-a]pyridin-3-amine derivatives from 2-aminopyridin, malononitrile and arylaldehydes in the presence of NaOH under solvent-free and conventional heating condition in good to excellent yields. A wide range of aromatic aldehydes would easily undergo condensations with 2-aminopyridin and malononitrile under solvent-free conditions in order to afford the desired products of good purity in excellent yields. For optimization of this reaction, the effect of NaOH amounts and use of other bases such as Et3N and Na2CO3 instead of NaOH and the efficacy of time and temperature to the reaction yields were studied. The use of simple and readily available starting materials, pharmacologically interest product, short reaction times, and applications in bioorganic and medicinal chemistry are the main advantages of this reaction.
![Unexpected one pot pseudo four-component reaction for the synthesis of (10E)-N-benzylidene-2-phenylH-imidazo [1,2-a]pyridin-3-amine derivatives under solvent-free conditions](data/icc/coversheet/191423033453.png)
Physical chemistry
Venugopal Rajendran; Varathan Selvaraj; Kuppusamy Harikumar
Volume 5, Issue 4, pp. 364-493, Serial No. 17 , October 2017, , Pages 381-396
Abstract
A new multi-site phase-transfer catalyst (MPTC), viz., N,N’-dioctyl-4,4’-bipyridium dibromide containing bi-site was prepared and proved by FT-IR, 1H NMR, 13C NMR, mass and elemental analysis. The enhancement of C-N+ peak intensity at 1179 cm−1 noticed in FT-IR, the agreement of m/z ...
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A new multi-site phase-transfer catalyst (MPTC), viz., N,N’-dioctyl-4,4’-bipyridium dibromide containing bi-site was prepared and proved by FT-IR, 1H NMR, 13C NMR, mass and elemental analysis. The enhancement of C-N+ peak intensity at 1179 cm−1 noticed in FT-IR, the agreement of m/z values, viz., 542.43 bi-site respectively with their theoretical values and the percentage of C, H, N elements noticed in elemental analysis has strongly supported the presence of tri-site MPTC catalysts. Further, the presence of number of active-sites in the catalyst was again confirmed by determining their pseudo-first order rate constant for dichlorocarbene addition to 1,3-bis(allyloxy)-5-methylbenzene in the presence of ultrasonic irradiation/mechanical stirring. The comparative study reveals that the kapp determined with the combination of ultrasound and mechanical stirring has shown more activity than with their individual effect. Further, the detailed kinetic study performed with superior di-site MPTC reveals that the kapp are dependent with the stirring speed, [substrate], [catalyst], [NaOH] and temperature. Based on the kinetic results, thermodynamic parameters are evaluated.
Inorganic chemistry
Mahdieh Ghobadifard; Qasem Maleki; Mostafa Khelghati; Ehsan Zamani; Saeid Farhadi; Alireza Aslani
Volume 3, Issue 1, pp. 1-71, Serial No.6 , January 2015, , Pages 26-40
Abstract
ZnO nanostructures of different methods and sizes were grown in a controlled manner using a simple hydrothermal and sonochemical technique. Controlling the content of concentration and temperature of the reaction mixture, spherical nanoparticles ZnO structures could be synthesized at temperatures 100-150 ...
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ZnO nanostructures of different methods and sizes were grown in a controlled manner using a simple hydrothermal and sonochemical technique. Controlling the content of concentration and temperature of the reaction mixture, spherical nanoparticles ZnO structures could be synthesized at temperatures 100-150 °C with excellent reproducibility in solvothermal and at different power and time in sonochemical methods. These ZnO nanostructures have been tested for CO2 gas monitoring by depositing them as thick films on an inter-digitated alumina substrate and evaluating the surface resistance of the deposited layer as a function of operating temperature and CO2 concentrations. The gas sensitivity tests have demonstrated that the ZnO nanostructures, spherical morphology, exhibit high sensitivity to CO2 proving their applicability in gas sensors. The role of the nanostructure on the sensing properties of ZnO is also discussed.
Physical chemistry
Alireza Amini khouzani; Nasrin Sohrabi; Nahid Rasouli; Mahboube Eslami Moghadam
Volume 6, Issue 1, pp. 1-108, Serial No. 18 , January 2018, , Pages 30-38
Abstract
In this study, a nickel (II) complex with 1,10-phenanthroline based ligand, [Ni(FIP)2](OAC)2 (1) with FIP = 2-(Furan-2-yl)-1H-Imidazole[4,5-f][1,10] phenanthroline as ligand was synthesized and characterized by spectroscopic methods and elemental analysis. The interaction of [Ni(FIP)2](OAC)2 (1) with ...
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In this study, a nickel (II) complex with 1,10-phenanthroline based ligand, [Ni(FIP)2](OAC)2 (1) with FIP = 2-(Furan-2-yl)-1H-Imidazole[4,5-f][1,10] phenanthroline as ligand was synthesized and characterized by spectroscopic methods and elemental analysis. The interaction of [Ni(FIP)2](OAC)2 (1) with calf-thymus DNA (ct-DNA) was studied by UV-vis absorption, fluorescence spectroscopies and viscosity measurements in 20 mM Tris/HCl buffer solution, pH 7.0 at 25 °C. The complex (1) interacts with ct-DNA with an intrinsic binding constant of 1.11 ×105 M-1. Furthermore, the thermodynamic studies suggested that the interaction processes were endothermic disfavored (ΔH >0) and entropy favored (ΔS >0). The viscosity studies showed no considerable increasing changes in the viscosity of ct-DNA with increasing of the complex (1) concentration. Therefore, the [Ni(FIP)2](OAC)2 complex bind to ct-DNA via hydrophobic interaction as the main forces acting during the binding processes and the mode of binding is groove binding which was illustrated by hyperchromism in the UV-vis absorption band of [Ni(FIP)2](OAC)2 (1) with addition of ct-DNA and the decreasing of ethidium bromide (EB)-ct-DNA complex fluorescence in the presence of different concentrations of [Ni(FIP)2](OAC)2 complex and the unchanged viscosity of ct-DNA.
Organic chemistry
Mehrdad Mahkam; Mehdi Nabati; Hadieh Rahbar Kafshboran
Volume 2, Issue 1, pp. 1-81, Serial No. 2 , January 2014, , Pages 34-38
Abstract
Lawsone a natural pigment present in the henna leaves has been used as a skin and hair dye since 1400 BC. The concentration of this natural compound in leaves varies from place to place depending upon many of the environmental factors and the highest quantity reported so far is about 1% of the dry mass. ...
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Lawsone a natural pigment present in the henna leaves has been used as a skin and hair dye since 1400 BC. The concentration of this natural compound in leaves varies from place to place depending upon many of the environmental factors and the highest quantity reported so far is about 1% of the dry mass. Heretofore, it has been reported that natural colored extracts and isolate from Henna leaves with many methods such as maceration, digestion, microwave and infusion. In this paper, regarding the therapeutic effects and traditional applications of henna, it was tried to isolate and characterize Lawsone from the henna leaves marketed in Tabriz city of Iran by soxhlet extraction technique in methanol solvent. The advantage of this technique is the isolation of large amounts of lawsone (720 mg from 40 g henne leaves powder) with smaller quantity of methanol.
Organic chemistry
Rashid Heidarimoghadam; Seyede Shima Mortazavi; Abbas Farmany
Abstract
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 ...
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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 (pIC50) of 2,5-diaminobenzophenone derivatives. Comparison of errors and correlation coefficients obtained by the models it was shown that the LM ANN approach works with a high correlation coefficient and low prediction error. This model was applied to the prediction of pIC50 values of 2,5-diaminobenzophenone derivatives. Applying the extended model to a dataset of 20 compounds demonstrate the reliability and accuracy of the model. Comparing three models revealed the superiority of the L-M ANN to predict the pIC50 of 2,5-diaminobenzophenones derivatives.
Organic chemistry
Ali Jafari; Ali Ramazani; Sang Woo Joo; Yavar Ahmadi; Fariba Sadri; Pegah Azimzadeh Asiabi
Volume 4, Issue 1, pp. 1-132, Serial No. 10 , January 2016, , Pages 42-56
Abstract
A green and convenient protocol is described for the preparation of 1-(alkylamino)-3-(1,3-dioxoisoindolin-2-yl)-2-methyl-1-oxopropan-2-yl benzoates via one-pot three-component reaction between 2-(2-oxopropyl)isoindoline-1,3-dione, an alkyl isocyanide and an aromatic carboxylic acid in water at room temperature. ...
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A green and convenient protocol is described for the preparation of 1-(alkylamino)-3-(1,3-dioxoisoindolin-2-yl)-2-methyl-1-oxopropan-2-yl benzoates via one-pot three-component reaction between 2-(2-oxopropyl)isoindoline-1,3-dione, an alkyl isocyanide and an aromatic carboxylic acid in water at room temperature. The methods used to follow the reactions are TLC and NMR, which indicated that there is no side product and the products were obtained without any purification. The structures of the products were deduced from their 1H NMR, 13C NMR and IR spectra. The present methodology offers several advantages such as a simple procedure, catalyst-free, mild reaction conditions, high yields, and the absence of any volatile and hazardous organic solvents.
Organic chemistry
Mohammad Javad Taghizadeh; Khosrow Jadidi
Volume 3, Issue 2, pp. 72-147, Serial No. 7 , April 2015, , Pages 96-104
Abstract
The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reaction of azomethine ylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature ...
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The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reaction of azomethine ylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imine)–Cu(II)triflate complex as catalyst.The reaction mechanism is discussedon the basis of the assignment of the absolute configuration of the cycloadducts.The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reaction of azomethine ylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imine)–Cu(II)triflate complex as catalyst.The reaction mechanism is discussedon the basis of the assignment of the absolute configuration of the cycloadducts.
Organic chemistry
Hamid Saeidian; Masomeh Faghfori; Morteza Abdoli
Abstract
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 ...
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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 A3 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 1H NMR, 13C NMR and EI-MS and comparison with authentic samples prepared by reported methods
Analytical chemistry
Sabah Shiri; Moayd Avazpour; Ali Delpisheh; Maryam Loeimyd
Volume 2, Issue 2, pp. 82-163, Serial No. 3 , April 2014, , Pages 119-128
Abstract
ABSTRACTA novel floatation-spectrophotometric extraction method was developed for the recovery of tin (II) from aqueous samples prior to determination by UV spectrophotometric detection. The method is based on the formation of a complex between tin (II) and kalmagyte in pH=8. The complex is floated in ...
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ABSTRACTA novel floatation-spectrophotometric extraction method was developed for the recovery of tin (II) from aqueous samples prior to determination by UV spectrophotometric detection. The method is based on the formation of a complex between tin (II) and kalmagyte in pH=8. The complex is floated in the interface of n-hexane and aqueous phases. After removing the aqueous phase, the floated particles are dissolved in methanol and the absorbance is measured at 637 nm. Different parameters of the floatation-spectrophotometric technique such as reagent concentration, pH, surfactant, standing time and interfering ions were studied and optimized to obtain the best extraction results with the minimum interference from other compounds. Under these conditions, the extraction of the target compound was almost complete (mean values of recovery was more than 92.6%) in a short time (6 min). The optimized method demonstrated good linearity (r2 > 0.9991) in the range of 4-350 ng/mL, sensitivity (limit of detection for tin (II), 1.7 ng/mL), accuracy (0.19–7.35%) and precision (3.66%, 4.21%). The applicability of the proposed method was demonstrated by extraction of tin(II) from different water samples.
Organic chemistry
Mosadegh Keshavarz
Volume 6, Issue 2, pp. 109-217, Serial No. 19 , April 2018, , Pages 134-142
Abstract
A facile and one-pot multicomponent synthesis of novel 1,4-disubstituted-1H-1,2,3-triazoles from alkenes at room temperature is reported. At the first step, in the presence of I2/NaN3 reagents, various alkenes were converted to the corresponding azido iodides and in the next step, the reaction of these ...
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A facile and one-pot multicomponent synthesis of novel 1,4-disubstituted-1H-1,2,3-triazoles from alkenes at room temperature is reported. At the first step, in the presence of I2/NaN3 reagents, various alkenes were converted to the corresponding azido iodides and in the next step, the reaction of these compounds with phenylacetylene in the presence of catalytic amount of sodium ascorbate/ CuSO4 afforded regioselective synthesis of 1,4-disubstituted-1H-1,2,3-triazoles in short times and at good to high yields. This greenapproach has several advantages such as short reaction times, clean reaction profiles, and simple experimental and workupprocedures. All the products were fully characterized by 1HNMR, 13CNMR, IR and CHN analysis
Organic chemistry
Gholamhassan Imanzadeh; Hamideh Vakili
Volume 5, Issue 2, pp. 121-236, Serial No. 15 , April 2017, , Pages 147-155
Abstract
A simple, efficient and clean procedure has been developed for the cleavage of imines C=N bond. Deprotection of imines to their parent carbonyl and amine compounds was achieved using p-toluenesulfonic acid in the solid state condition at 25-45 ˚C. The salient features of this methodology are shorter ...
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A simple, efficient and clean procedure has been developed for the cleavage of imines C=N bond. Deprotection of imines to their parent carbonyl and amine compounds was achieved using p-toluenesulfonic acid in the solid state condition at 25-45 ˚C. The salient features of this methodology are shorter reaction times, cheap processing, high yields of product and easy availability of the catalyst. These features make this method an attractive alternative to existing routes for deprotection of iminesA simple, efficient and clean procedure has been developed for the cleavage of imines C=N bond. Deprotection of imines to their parent carbonyl and amine compounds was achieved using p-toluenesulfonic acid in the solid state condition at 25-45 ˚C. The salient features of this methodology are shorter reaction times, cheap processing, high yields of product and easy availability of the catalyst. These features make this method an attractive alternative to existing routes for deprotection of imines
Organic chemistry
Fatemeh Kalantari; Ali Ramazani; Fatemeh Zeinali Nasrabadi
Volume 4, Issue 2, pp. 133-235, Serial No. 11 , April 2016, , Pages 155-164
Abstract
The imine intermediate generated by the addition of primary amine to the cinnamaldehyde is trapped by the N-isocyaniminotriphenylphosphorane (Ph3PNNC) and a carboxylic acid, and leads to the formation of the corresponding iminophosphorane intermediate. The 1,3,4-oxadiazole derivatives are formed via ...
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The imine intermediate generated by the addition of primary amine to the cinnamaldehyde is trapped by the N-isocyaniminotriphenylphosphorane (Ph3PNNC) and a carboxylic acid, and leads to the formation of the corresponding iminophosphorane intermediate. The 1,3,4-oxadiazole derivatives are formed via intramolecular aza-Wittig reaction of the iminophosphorane intermediate. The reactions were completed under neutral conditions at room temperature. The fully substituted 1,3,4-oxadiazole derivatives were produced in high yields. The method offers a mild, simple, and efficient route for the preparation of fully substituted 1,3,4-oxadiazols. The structures of the products were deduced from their IR, 1H NMR, 13C NMR spectra, and mass spectrometry.
Organic chemistry
Parya Nasehi; Alireza Kiasat; Mohammad Kazem Mohammadi
Volume 2, Issue 3, pp. 162-231, Serial No. 4 , July 2014, , Pages 180-186
Abstract
3,4-dihydropyrimidin-2(1H)-thiones were synthesized in the presence of Ag nanoparticle/melamine sulfonic acid (MSA) supported on silica gel. The reaction was carried out at 110 oC for 20 min under solvent free conditions. In all cases, the three component reaction proceeded smoothly to give the corresponding ...
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3,4-dihydropyrimidin-2(1H)-thiones were synthesized in the presence of Ag nanoparticle/melamine sulfonic acid (MSA) supported on silica gel. The reaction was carried out at 110 oC for 20 min under solvent free conditions. In all cases, the three component reaction proceeded smoothly to give the corresponding 3,4-dihydropyrimidin-2(1H)-thiones in moderate to good yield. We have found the best conditions are using 0.2 g MSA, 0.05 g Ag nanoparticle.SiO2 under solvent free conditions at 110 oC. This method have some advantages such as good yield, mild reaction conditions, ease of operation and work up, short reaction time and high product purity. In this work, we have investigated the application of Ag nanoparticle/MSA.SiO2 for synthesis of Biginelli – type condensation.
Physical chemistry
Ashraf M Ashmawy; Maher I Nessim; Doaa I Osman; El Sayed M Elnaggar
Abstract
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, ...
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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, 1H-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 was 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.
Organic chemistry
Paat Josefa; figueroa Lauro; Lopez Maria; Hau Lenin; Diaz Francisco; Garcia Elodia; Pool Eduardo; rosas Marcela; Mateu Virginia
Volume 6, Issue 3, pp. 218-324, Serial No. 20 , July 2018, , Pages 256-265
Abstract
The aim of this study was to synthesize a new oxetan-phenyltetrahydropyridazine-3,6-dione derivative (compound 6) using with different techniques. The first method was achieved by the preparation of a phenylhydrazine derivative (2) using three components system (3,17-aldol-estradiol, phenylhydrazine, ...
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The aim of this study was to synthesize a new oxetan-phenyltetrahydropyridazine-3,6-dione derivative (compound 6) using with 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 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 a 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, in this study a facile method to synthesis of an oxetan-phenyltetrahydropyridazine-3,6-dione is reported.
Organic chemistry
Ashraf Sadat Shahvelayati; Leila Hajiaghababaei; Akram Panahi Sarmad
Volume 5, Issue 3, pp. 237-363, Serial No. 16 , July 2017, , Pages 262-267
Abstract
In this research, an efficient synthesis toward 2-(2-((4-Methoxybenzoyl)imino)-4-(4-methoxyphenyl)thiazol-3(2H)-yl)-2-phenylacetic acid via a three-component tandem reaction using aroylisothiocyanate, phenyl glycine, and 4-methoxyphenacyl bromide in an ionic liquid (IL) has been described. 1-Methyl-3-pentylimidazolium ...
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In this research, an efficient synthesis toward 2-(2-((4-Methoxybenzoyl)imino)-4-(4-methoxyphenyl)thiazol-3(2H)-yl)-2-phenylacetic acid via a three-component tandem reaction using aroylisothiocyanate, phenyl glycine, and 4-methoxyphenacyl bromide in an ionic liquid (IL) has been described. 1-Methyl-3-pentylimidazolium bromide (IL) has been employed as a recyclable green solvent. The work-up procedure was fairly simple and the product did not require further purification. The influence of various reaction parameters such as solvent, temperature, and time was examined and among the various solvents such as ethanol, acetonitrile, n-hexane, water, and ionic liquid for synthesis of the final product, the best result was obtained in 1-methyl-3-pentylimidazolium bromide at 50oC for 1 hours.
Applied Chemistry
Omid Louie; Abdoulhossien Massoudi; Samaneh Maghsoodi
Volume 2, Issue 4, pp. 236-325, Serial No. 5 , October 2014, , Pages 269-276
Abstract
Supramolecule self assembly polyamidoamine (PAMAM) dendrimer refers to the chemical systems made up of a discrete number of assembled molecular subunits or components. These strategies involve the covalent assembly of hierarchical components reactive monomers, branch cells or dendrons around atomic or ...
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Supramolecule self assembly polyamidoamine (PAMAM) dendrimer refers to the chemical systems made up of a discrete number of assembled molecular subunits or components. These strategies involve the covalent assembly of hierarchical components reactive monomers, branch cells or dendrons around atomic or molecular cores according to divergent/convergent dendritic branching principles, systematic filling of space around a core with shells (layers) of branch cells. The polydispersity index (PDI) for the Supramolecule megamer are pretty closed to one, are in agreement with the Poisson probability distribution. Polyamidoamine (PAMAM) dendrimer G1-G1 that it was PAMAM Megamer NH2, COOH end group synthesized and characterized by FT-IR, 1H NMR, 13C NMR spectra and Gel Permeation Chromatography (GPC).
Organic chemistry
Hamideh Javanbani; Ali Ramazani; Sang Woo Joo; Yavar Ahmadi; Vahid Azizkhani; Pegah Azimzadeh Asiabi
Volume 3, Issue 4, pp. 283-387, Serial No. 9 , October 2015, , Pages 310-322
Abstract
Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular Aza-Wittig ...
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Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular Aza-Wittig cyclization in CH2Cl2 in excellent yields. The structures of the products were deduced from their IR, Mass, ¹H NMR, and ¹³C NMR spectra. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed. The method offers a mild, simple, and efficient route for the preparation of fully substituted 1,3,4-oxadiazoles from cyclopentanone, primary amines, N-isocyaniminotriphenylphosphorane and aromatic carboxylic acids. Easy work-up, high yields and fairly mild reaction conditions make it a useful procedure in comparison to the modern synthetic methodologies.
Analytical chemistry
Mohammad Rezaiati; Farhad Salimi; Changiz Karami
Volume 5, Issue 4, pp. 364-493, Serial No. 17 , October 2017, , Pages 397-406
Abstract
Chromium is one of the hazardous pollutants in industrial effluents. In this study, a new nano-boehmite modified with sodium dodecyl sulphate is developed for preconcentration trace amounts of chromium ions as a prior step to its determination by flame atomic absorption spectrometry. We investigated ...
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Chromium is one of the hazardous pollutants in industrial effluents. In this study, a new nano-boehmite modified with sodium dodecyl sulphate is developed for preconcentration trace amounts of chromium ions as a prior step to its determination by flame atomic absorption spectrometry. We investigated the effect of various parameters on the recovery of the analyte ions, including pH of sample solution, amount of sorbent, sample volume on extraction efficiency of the chromium ions. Under the best experimental conditions, the calibration curve was linear in the range of 1.0 -700.0 ng.mL-1 of chromium with R2 = 0.997. Detection limit was 0.6 ng.mL-1 in the original solution (3Sb/m) and the relative standard deviation for seven replicate determination of 0.5 µg.mL-1 chromium was ±2.4%. The developed method was successfully applied to the extraction and determination of chromium in water and food samples with satisfactory results.
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