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Articles 1531 - 1560 of 2628
Full-Text Articles in Physical Sciences and Mathematics
Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi
Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi
Turkish Journal of Chemistry
A new class of optically active polyamides (PAs) (6a-e) having 4-nitro-1,3-dioxoisoindolin-2-yl pendent groups were prepared by direct polycondensation reaction of 2-(4-nitro-1,3-dioxoisoindolin-2-yl) succinic acid (4) with various aromatic diamines in a medium consisting of triphenyl phosphite, calcium chloride, pyridine, and N-methyl-2-pyrrolidone. The resulting new polymers were obtained in high yields with inherent viscosities ranging between 0.32 and 0.48 dL/g, and were characterized by elemental analysis, FT-IR spectroscopy, specific rotation, solubility tests, and thermogravimetric analysis techniques (TGA and DTG). Bulky pendent groups of the polymer chains disturb interchain and intrachain interactions and make these PAs readily soluble in polar organic solvents such …
Synthesis And Uranyl Ion Adsorption Study Of Cross-Linked Allyl Propionate-Maleic Anhydride-Styrene Terpolymer, Elchin Akperov, Abel Maharramov, Oktay Akperov
Synthesis And Uranyl Ion Adsorption Study Of Cross-Linked Allyl Propionate-Maleic Anhydride-Styrene Terpolymer, Elchin Akperov, Abel Maharramov, Oktay Akperov
Turkish Journal of Chemistry
Allyl propionate-maleic anhydride-styren terpolymer has been modified with glycerin in order to prepare a new cross-linked functional polymer sorbent. The synthesized cross-linked polymer sorbent has a network structure and contains carboxylic acid, carbonyl, hydroxy, and ester groups, all of which are capable ofinteracting with metal ions. The sorption behavior of UO_2^{2+} ions under optimum sorption conditions was determined. The sorption properties of the sorbent were determined under different conditions by varying of the pH of medium, the sorbent weight, and the initial concentration of uranyl ions. The maximum experimental sorption capacity of the sorbent for uranyl ions was measured as …
Some Bioactive Organotin(Iv) Derivatives With 3,4-Dichlorophenylacetic Acid: Synthesis, Spectroscopic Properties, And X-Ray Structure Of [Sn_4(C_4h_9)_8(Oocch_2c_6h_3cl_2)_4o_2], Muhammad Adeel Saeed, Muhammad Khawar Rauf, . Imtiaz-Ud-Din, Amin Badshah, Muhammad Zaeem Akhtar, Bushra Mirza
Some Bioactive Organotin(Iv) Derivatives With 3,4-Dichlorophenylacetic Acid: Synthesis, Spectroscopic Properties, And X-Ray Structure Of [Sn_4(C_4h_9)_8(Oocch_2c_6h_3cl_2)_4o_2], Muhammad Adeel Saeed, Muhammad Khawar Rauf, . Imtiaz-Ud-Din, Amin Badshah, Muhammad Zaeem Akhtar, Bushra Mirza
Turkish Journal of Chemistry
Some bioactive organotin(IV) derivatives of 3,4-dichlorophenylacetic acid (HL) were synthesized by reacting the ligand acid with various di- or tri-organotin compounds (in suitable mole ratios) in the presence of triethylamine. The structural investigation was carried out via multinuclear (^1H, ^{13}C, and ^{119}Sn) NMR, IR spectroscopy, and X-ray crystallography. The crystal structure of 4 comprises a central Sn_2O_2 core with O atoms bonded to 2 dibutylbis(3,4-dichlorophenylacetato)tin(IV) units. All the Sn atoms of 4 are essentially 5-coordinated in distorted trigonal-bipyramidal geometry. Some of the compounds exhibited significant antibacterial and antifungal activity.
Density Functional Theory Investigation Of Electrophilic Addition Reaction Of Chlorine To Tricyclo[4.2.2.2^{2,5}]Dodeca-1,5-Diene, Rza Abbasoğlu, Ahmet Yaşar
Density Functional Theory Investigation Of Electrophilic Addition Reaction Of Chlorine To Tricyclo[4.2.2.2^{2,5}]Dodeca-1,5-Diene, Rza Abbasoğlu, Ahmet Yaşar
Turkish Journal of Chemistry
Potential energy surface (PES) of the tricyclo[4.2.2.2^{2,5}]dodeca- 1,5-diene (TCDD)-Cl_2 system was studied by B3LYP/6-311+G(d,p) method and the configurations [reactants, molecular charge-transfer (CT) complex, transition states (TS1 and TS2), intermediate (INT), and product (P)] corresponding to the stationary points (minima or saddle points) were determined. Initially, a molecular CT-complex forms between Cl_2 and TCDD. With a barrier of 22.362 kcal mol^{-1} the CT-complex can be activated to an intermediate (INT) with energy 14.682 kcal mol^{-1} higher than that of the CT-complex. The intermediate (INT) then transforms easily (barrier 5.102 kcal mol^{-1}) into the final, N-type product. Accompanying the breaking of the …
Interference Elimination Studies During The Determination Of Trace Elements In Cow Liver Using Differential Pulse Polarography, Ümmi̇han T. Yilmaz, Güler Somer
Interference Elimination Studies During The Determination Of Trace Elements In Cow Liver Using Differential Pulse Polarography, Ümmi̇han T. Yilmaz, Güler Somer
Turkish Journal of Chemistry
The liver is known to accumulate many trace elements; thus it is very important to determine their level in a sensitive way. The objective of this study was to develop a simple method for the simultaneous determination of trace elements in cow liver in which the elimination of interference can be accomplished. It was observed that Cd, Pb, Zn, and Cu ions could not be determined correctly in the presence of Se(IV), because of interference of Se. It was shown that this interference could be eliminated by using pH 8.5 NaAc electrolyte. In this medium first Cd and Zn were …
Template Synthesis And Characterization Of 16-Membered Octaazamacrocyclic Complexes: A Photoelectron Spectroscopic Study, Abul Kalam, Vishnu Tripathi, Shekhar Srivastava, Yogesh Pandey, Anil Kumar, Alok Gupta, Sharat Srivastava, Ankoor Purohit
Template Synthesis And Characterization Of 16-Membered Octaazamacrocyclic Complexes: A Photoelectron Spectroscopic Study, Abul Kalam, Vishnu Tripathi, Shekhar Srivastava, Yogesh Pandey, Anil Kumar, Alok Gupta, Sharat Srivastava, Ankoor Purohit
Turkish Journal of Chemistry
A novel series of complexes of the type [MLX_2] where M= Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X= C^- or NO_3^- were synthesized by template condensation of hydrazine hydrate, acetaldehyde, 2,4-pentanedione, and thiocarbohydrazide in the presence of divalent metal salt in methanolic solution. The complexes were characterized with the help of elemental analysis, conductance measurements, magnetic measurements, electronic, NMR, XPS, and infrared and far infrared spectral studies. Electronic spectra along with magnetic moments suggest 6-coordinated octahedral geometry for these complexes. The low value of molar conductance indicates them to be non-electrolytes.
Determination Of Ceftriaxone, Ceftizoxime, Paracetamol, And Diclofenac Sodium By Capillary Zone Electrophoresis In Pharmaceutical Formulations And In Human Blood Serum, Amber Solangi, Saima Memon, Arfana Mallah, Najma Memon, Muhammad Yar Khuhawar, Muhammad Iqbal Bhanger
Determination Of Ceftriaxone, Ceftizoxime, Paracetamol, And Diclofenac Sodium By Capillary Zone Electrophoresis In Pharmaceutical Formulations And In Human Blood Serum, Amber Solangi, Saima Memon, Arfana Mallah, Najma Memon, Muhammad Yar Khuhawar, Muhammad Iqbal Bhanger
Turkish Journal of Chemistry
A simple and fairly fast capillary zone electrophoresis method has been developed for the determination and separation of ceftriaxone, ceftizoxime, paracetamol, and diclofenac sodium in a mixture, in pharmaceutical formulations, and in blood serum. A 50 mM sodium tetraborate background electrolyte solution (pH 9.0) was found to be suitable for separation of all the drugs. An uncoated fused-silica capillary of a total length of 57 cm (effective length 50 cm) was used for separation. All the analytes were completely separated within 8.0 min at an applied voltage of 30 kV and detection was performed at 214 nm .Validation of the …
Biotransformation Of Danazol By Fusarium Solani And Gibberella Fujikuorii, And Prolyl Endopeptidase Inhibition Studies Of Transformed Products, Azizuddin Shaikh, Muhammad Iqbal Choudhary
Biotransformation Of Danazol By Fusarium Solani And Gibberella Fujikuorii, And Prolyl Endopeptidase Inhibition Studies Of Transformed Products, Azizuddin Shaikh, Muhammad Iqbal Choudhary
Turkish Journal of Chemistry
Biotransformation of danazol (17\beta-hydroxy-17\alpha-pregna-2,4-dien-20-yno-[2,3-d] isoxazole) (1) on fermentation with Fusarium solani yielded 17\beta-hydroxy-2-(hydroxymethyl)-17\alpha -pregn-4-en-20-yn-3-one (2) and 17\beta -hydroxy-2-(hydroxymethyl)-17\alpha-pregna-1,4-dien-20-yn-3-one (3), while the fermentation of 1 with Gibberella fujikuorii yielded compound 2 only. The structures of these compounds were deduced on the basis of modern spectroscopic techniques. Prolyl endopeptidase inhibition activities of danazol (1) and its transformed products 2 and 3 are also studied.
Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu
Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu
Turkish Journal of Chemistry
The bacterial SEC pathway is commonly used for secretion of heterologous proteins in E. coli by fusing them to transported proteins to facilitate downstream processing. While some proteins are translocated very efficiently, some reside in the cytoplasm. In this work, maltose binding protein (MBP) was fused to 3 cytoplamic enzymes from Thermus thermophilus (serine protease, 251 residues; glucose isomerase, 381 residues; pullulanase, 718 residues) to study the protein transport from the cytoplasm by quantifying the distribution of activities in different cellular compartments. Pullulanase activity was harvested exclusively in the periplasm; however, glucose isomerase activity was harvested exclusively in the cytoplasm. …
Electro-Oxidation Of Some Non-Steroidal Anti-Inflammatory Drugs On An Alumina Nanoparticle-Modified Glassy Carbon Electrode, Mahla Tabeshnia, Hossein Heli, Ali Jabbari, Ali A. Moosavi-Movahedi
Electro-Oxidation Of Some Non-Steroidal Anti-Inflammatory Drugs On An Alumina Nanoparticle-Modified Glassy Carbon Electrode, Mahla Tabeshnia, Hossein Heli, Ali Jabbari, Ali A. Moosavi-Movahedi
Turkish Journal of Chemistry
The electro-oxidation of mefenamic acid, diclofenac, and indomethacin on glassy carbon and alumina nanoparticle-modified glassy carbon electrodes in a phosphate buffer solution at physiological pH was studied. The techniques of cyclic voltammetry, chronoamperometry, impedance spectroscopy, and steady state polarization measurements were applied. The drugs were irreversibly oxidized on bath electrodes via an anodic peak and the process was controlled by diffusion in the bulk of solution. Alumina nanoparticles increased the oxidation current, and lowered the peak and onset potentials. As such, alumina nanoparticles had an electrocatalytic effect, both kinetically and thermodynamically. The kinetic parameters of heterogeneous electron transfer and diffusion …
Influence Of Alcl_3 On The Optical Properties Of New Synthesized 3-Armed Poly(Methyl Methacrylate) Films, Adnan Kurt
Influence Of Alcl_3 On The Optical Properties Of New Synthesized 3-Armed Poly(Methyl Methacrylate) Films, Adnan Kurt
Turkish Journal of Chemistry
Three-armed poly(methyl methacrylate)[PMMA] was synthesized by atom transfer radical polymerization at 100 °C using benzene-1,3,5-triyl tris(4-(bromomethyl) benzoate as 3-armed initiator and a cuprous(I) bromide/2,2'-bipyridine catalytic system. The characterization of PMMA was confirmed by FT-IR, ^1H-NMR, GPC, DSC, and TGA techniques. Optical absorption measurements were also studied by UV-VIS technique. Transmittance and reflectance measured in the wavelength range 300-700 nm were used to calculate the optical constants. The changes in dispersion and Urbach parameters were investigated as a function of AlCl_3 content. The wide band tails increased in width and the optical energy gap decreased from 2.39 to 1.28 eV as …
Multichannel Spectrophotometry For Analysis Of Organophosphate Paraoxon In Beverages, Miroslav Pohanka, Jana Zdarova Karasova, Kamil Kuca, Jiri Pikula
Multichannel Spectrophotometry For Analysis Of Organophosphate Paraoxon In Beverages, Miroslav Pohanka, Jana Zdarova Karasova, Kamil Kuca, Jiri Pikula
Turkish Journal of Chemistry
Multichannel spectrophotometry was performed to assay for paraoxon in spiked beverages. A 96-well microplate was used for this purpose. The measuring protocol was based on inhibition of the enzyme acetylcholinesterase by paraoxon that resulted in decreased or no reaction of the enzyme product thiocholine with Ellman's reagent (5,5'-dithiobis [2-nitrobenzoic acid]). The above assay was practically tested using spiked drinking water, mineral water, and coffee. Analytical parameters such as the limit of detection, time, and sample size consumption were adequate. The limit of detection for beverages ranged from 32 to 48 ppb corresponding to 0.32-0.48 ng of paraoxon in absolute values. …
Ionic Liquids As Solvent For Efficient Esterification Of Carboxylic Acids With Alkyl Halides, Yetki̇n Gök, Bülent Alici, Engi̇n Çeti̇nkaya, İsmai̇l Özdemi̇r, Özlem Özeroğlu
Ionic Liquids As Solvent For Efficient Esterification Of Carboxylic Acids With Alkyl Halides, Yetki̇n Gök, Bülent Alici, Engi̇n Çeti̇nkaya, İsmai̇l Özdemi̇r, Özlem Özeroğlu
Turkish Journal of Chemistry
The selective esterification of carboxylic acid derivatives with a variety of alkyl halides was carried out using ionic liquid as solvent in the presence of triethylamine. The reaction was found to proceed under relatively mild conditions with excellent conversions (up to 99%) and selectivities. The ionic liquid was recycled and reused.
Chelating Agent Free Solid Phase Extraction (Caf-Spe) Method For Separation And/Or Preconcentration Of Iron(Iii) Ions, Özcan Yalçinkaya, Orhan Murat Kalfa, Ali̇ Rehber Türker
Chelating Agent Free Solid Phase Extraction (Caf-Spe) Method For Separation And/Or Preconcentration Of Iron(Iii) Ions, Özcan Yalçinkaya, Orhan Murat Kalfa, Ali̇ Rehber Türker
Turkish Journal of Chemistry
This paper presents a chelating agent free solid phase extraction (CAF-SPE) method for the separation and/or preconcentration of trace iron(III) ions. This method is based on the sorption of Fe(III) ions without using any chelating agent onto Amberlyst 36 resin. A good relative standard deviation (3%), high recovery (>95%), high enrichment factor (100), and low detection limit (0.32 \mu g L^{-1}) were obtained. The adsorption capacity of resin was 117 mg g^{-1} for iron(III). The method was applied for the determination of iron various in water and commercial tea bag samples. The accuracy of the method was confirmed by …
Isolation Of Bis(1,4-Diphenyl-1,4-Bis(2-Pyridyl)-2,3-Diaza-1,3-Butadiene) Disilver With Bridging (N-N) Dinucleating Subunits: Formation Of A 6-Membered Chelate Ring, Amitabha Datta, Neerish Revaprasadu
Isolation Of Bis(1,4-Diphenyl-1,4-Bis(2-Pyridyl)-2,3-Diaza-1,3-Butadiene) Disilver With Bridging (N-N) Dinucleating Subunits: Formation Of A 6-Membered Chelate Ring, Amitabha Datta, Neerish Revaprasadu
Turkish Journal of Chemistry
A novel Ag(I) dinuclear complex {[(C_6H_5)(C_5H_4N)-C=N-N=C- (C_5H_4N)(C_6H_5)]Ag}_2.ClO_4(ClO_4) (1/2CH_3CN) (1) that was derived under mild conditions, during the course of combination of AgClO_4 with a polymorphic azine ligand, 1,4-diphenyl-1,4-bis(2-pyridyl)-2,3- diaza-1,3-butadiene (L) (condensed product of phenyl 2-pyridyl ketone and hydrazine monohydrate) is reported. The aforementioned complex is based on a central rotationally flexible diazine subunit (N-N). The azine ligand, L, having the N_2 dinucleating fragment, provides a coordination focus for pairs of metal centres and ultimately leads to the formation of a 6-membered chelate ring in 1.
Comparative Kinetic Studies On The Alkaline Hydrolysis Of Halogen Substituted Isocoumarins, Hafiz Badaruddin Ahmad, Muhammad Aslam Malana, Muhammad Yousaf, Muhammad Rehan, Mazhar Abbas
Comparative Kinetic Studies On The Alkaline Hydrolysis Of Halogen Substituted Isocoumarins, Hafiz Badaruddin Ahmad, Muhammad Aslam Malana, Muhammad Yousaf, Muhammad Rehan, Mazhar Abbas
Turkish Journal of Chemistry
Kinetics of the hydrolysis of 3-(2'-chloro-6'-fluorobenzyl) isocoumarin (1), 3-(4'-fluorophenyl)isocoumarin (3), 3-(2'- fluorophenyl)isocoumarin (5), 3-(2'-chlorophenyl)isocoumarin (7), and 3-(4'-chlorophenyl)isocoumarin (9) were studied spectrophotometrically in the presence of aqueous solution of potassium hydroxide. The rates of hydrolyses for these isocoumarins were compared. The data for isocoumarin (1) were further investigated to probe the reaction mechanism. The dependence of pseudo-first order rate constant k_{obs} on hydroxide ion concentration is fitted by the expression k_{obs} = k_o + k_1[OH] + k_2 [OH]^2, showing the formation of monoanionic and dianionic tetrahedral intermediates during the course of reaction. The magnitude of k_o shows significant participation of solvent …
A Theoretical Study Of The Effects Of Polar Substitution On The Activation Barriers For Internal Rotation Around The C-N Bond In P-Substituted Nitrosobenzenes: Comparison Of Dft And Mp2 Calculations, Şafak Özhan Kocakaya, Necmetti̇n Pi̇ri̇nççi̇oğlu
A Theoretical Study Of The Effects Of Polar Substitution On The Activation Barriers For Internal Rotation Around The C-N Bond In P-Substituted Nitrosobenzenes: Comparison Of Dft And Mp2 Calculations, Şafak Özhan Kocakaya, Necmetti̇n Pi̇ri̇nççi̇oğlu
Turkish Journal of Chemistry
The activation barriers for internal rotation around the C-N bond in p-substituted nitrosobenzenes were calculated using the density functional theory (DFT) and second-order Møller-Plesset (MP2) methods with the 6-31+g(d) basis set. The polarisable continuum model (PCM) was used to model the solvent effect. An explicit water molecule was also introduced to form a hydrogen bond with the nitrosogroup and its effect on the barrier was studied by DFT. The barriers were well-correlated with Hammett sigma^+ rather than sigma values, meaning a strong resonance effect. The MP2 method produces better and comparable results with the few available experimental values.
An Efficient One-Pot Synthesis Of Dihydropyrimidinones Catalyzed By Zirconium Hydrogen Phosphate Under Solvent-Free Conditions, Mustafa Küçüki̇slamoğlu, Şenol Beşoluk, Mustafa Zengi̇n, Mustafa Arslan, Mehmet Nebi̇oğlu
An Efficient One-Pot Synthesis Of Dihydropyrimidinones Catalyzed By Zirconium Hydrogen Phosphate Under Solvent-Free Conditions, Mustafa Küçüki̇slamoğlu, Şenol Beşoluk, Mustafa Zengi̇n, Mustafa Arslan, Mehmet Nebi̇oğlu
Turkish Journal of Chemistry
A simple, efficient, and practical procedure for the Biginelli reaction using zirconium hydrogen phosphate [Zr(H_2PO_4)_2] as a novel solid acid catalyst is described under solvent-free conditions in high yields. The catalyst exhibited remarkable reactivity and it is reusable.
Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu
Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
2-(4-Amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H-1,2,4-triazol- 1-yl)-N'-[(2,6-dihalogenophenyl)-methylene]acetohydrazides (3a,b) was obtained via the formation of 2-(4-amino-3-(4-chlorophenyl)-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl)acetohydrazide (2), which was obtained starting from 4-amino-5-(4-chlo\-rophenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (1) in 2 steps. 2-{[4-amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H- 1,2,4-triazol-1-yl]acetyl}-N-phenylhydra-zine carbothioamide (4), which was prepared starting from 2, was converted to the corresponding 1,3,4-thiadiazole derivative (5) in acidic media. Moreover, the basic treatment of 4 resulted in the formation of 4-amino-5-(4-chlorophenyl)- 2-[(4-phenyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl]-2,4- dihydro-3H-1,2,4-triazol-3-one (7). The reactions of compounds 5 and 7 with methyl iodide in the presence of sodium ethoxide afforded the corresponding N-methyl (6) and S-methyl (8) derivatives, respectively. The synthesis of Mannich bases (10a and 10b) was performed from the reaction of 7 with …
Preparation Of Polystyrene/Montmorillonite Nanocomposites: Optimization By Response Surface Methodology (Rsm), Sadik Erdem Yalçinkaya, Nuray Yildiz, Mehmet Saçak, Ayla Çalimli
Preparation Of Polystyrene/Montmorillonite Nanocomposites: Optimization By Response Surface Methodology (Rsm), Sadik Erdem Yalçinkaya, Nuray Yildiz, Mehmet Saçak, Ayla Çalimli
Turkish Journal of Chemistry
Preparation of polystyrene (PS)-montmorillonite nanocomposites was carried out in 3 steps: purification and determination of the cation exchange capacity (CEC) of clay, synthesis of organoclay, and preparation of nanocomposites. In organoclay synthesis, 3 types of surfactants, long-chained (cetyltrimethylammonium bromide (CTAB)), short-chained (tetraethylammonium bromide (TEAB)), and ringed (benzyltriethylammonium bromide (BTEAB)), were used. Gallery distances of pure clay and organoclays (CTAB-O, TEAB-O, and BTEAB-O) were determined by X-ray diffraction (XRD) analysis as 1.25, 2.09, 1.52, and 1.63 nm, respectively. Preparation of nanocomposites was carried out by in situ polymerization. Composites, containing 2%, 4%, and 6% organoclay by mass, were characterized by XRD, …
Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri
Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri
Turkish Journal of Chemistry
An efficient one-pot method for the synthesis of 1,4-dihydropyridines from \beta-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 °C under solvent-free conditions with good to excellent yields. The catalyst is easily prepared, stable (up to 300 °C), reusable, and efficiently used under reaction conditions.
Friedel-Crafts Acylation Of Arenes With Carboxylic Acids Using Silica Gel Supported Alcl_3, Kaveh Parvanak
Friedel-Crafts Acylation Of Arenes With Carboxylic Acids Using Silica Gel Supported Alcl_3, Kaveh Parvanak
Turkish Journal of Chemistry
Aromatic compounds react smoothly with carboxylic acids in the presence of silica gel supported aluminium trichloride to afford the corresponding ketones with high regioselectivity in high to excellent yields. The catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency.
Chemistry Of 2-Aminoanthraquinones, Mostafa Gouda, Moged Berghot, Alaa Shoeip, Khaled Elattar, Abd El Galil Khalil
Chemistry Of 2-Aminoanthraquinones, Mostafa Gouda, Moged Berghot, Alaa Shoeip, Khaled Elattar, Abd El Galil Khalil
Turkish Journal of Chemistry
This review represents a systematic and comprehensive survey of the methods of preparation and the chemical reactivity of 2-aminoanthraquinone. This compound is an important intermediate for the synthesis of a variety of otherwise difficult to obtain synthetically useful and novel heterocyclic systems.
Synthesis, Spectroscopic Characterization, Mass Spectrometry, And Crystal Structure Of N-{[(4-Bromophenyl)Amino]Carbonothioyl}Benzamide, Sohail Saeed, Naghmana Rashid, Moazzam Bhatti, Peter Jones
Synthesis, Spectroscopic Characterization, Mass Spectrometry, And Crystal Structure Of N-{[(4-Bromophenyl)Amino]Carbonothioyl}Benzamide, Sohail Saeed, Naghmana Rashid, Moazzam Bhatti, Peter Jones
Turkish Journal of Chemistry
N-{[(4-bromophenyl)amino]carbonothioyl}benzamide was synthesized and characterized by IR, ^1H- and ^{13}C-NMR, mass spectrometry, and elemental analysis. The crystal structure was determined from single crystal X-ray diffraction data. It crystallizes in monoclinic space group P2_1/n with unit cell dimensions a = 13.822(3) Å, b = 5.927(2) Å, c = 16.642(3) Å, and \beta = 103.963(3)°. There is a strong intramolecular hydrogen bond of the type N__H \Lambda O, with an H\Lambda O distance of 2.6129 (11) Å. The mass fragmentation pattern is also discussed.
Isolation And Identification Of A New Acetildenafil Analogue Used To Adulterate A Dietary Supplement: Dimethylacetildenafil, Ali̇ Hakan Göker, Maksut Coşkun, Mehmet Alp
Isolation And Identification Of A New Acetildenafil Analogue Used To Adulterate A Dietary Supplement: Dimethylacetildenafil, Ali̇ Hakan Göker, Maksut Coşkun, Mehmet Alp
Turkish Journal of Chemistry
A new sildenafil analogue was found to have been added illegally to a dietary supplement marketed for the enhancement of sexual function. The structure was determined as 5-(2-ethoxy-5- {[4-(3,5-dimethyl)piperazin-1-yl]-acetyl}phenyl)-1,6-dihydro-1-methyl-3- propyl-7H-pyrazolo [4,3-d]pyrimidin-7-one. Owing to the inclusion of a dimethyl group in acetildenafil, the detected compound was called dimethylacetildenafil. The sample was purified with column chromatography. The IR, LC/MS (ESI), and completely assigned NMR data of dimethylacetildenafil are reported for the first time. The structure was compared with that of acetildenafil and the results showed that the ethyl substitution at the 4-position of the piperazine ring had been replaced by a 3,5-dimethyl …
Synthesis Of Some New Biheterocyclic Triazole Derivatives And Evaluation Of Their Antimicrobial Activity, Hakan Bektaş, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Synthesis Of Some New Biheterocyclic Triazole Derivatives And Evaluation Of Their Antimicrobial Activity, Hakan Bektaş, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
2-{3-(4-Substitutedbenzyl)-4-[2-(1H-indol-3-yl)ethyl]-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl}-N'-(aryl-methylene)acetohydrazides (5a-g), 4-amino-2-{-(4-substitutedbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol- 1-yl}-N'-(arylmethylene)acetohydrazides (6a,b), and 4-[2-(1H-indol- 3-yl)ethyl]-5-(4-substitutedbenzyl)-2-{5-(phenylamino)-1,3,4-thiadiazol- 2-yl]methyl}-2,4-dihydro-3H-1,2,4-triazol-3-ones (8a,b) were synthesized starting from 4-alkyl-5-(4-substitutedbenzyl)-2,4-dihydro- 3H-1,2,4-triazol-3-ones (2a-c) by several steps and their structures were well characterized by elemental analyses, IR, ^1H-NMR, ^{13}C-NMR, and mass spectral studies. They were also screened for their microbial activities. The obtained antimicrobial activity results revealed that 12 among the 24 compounds tested displayed variable growth inhibition effects on the tested gram-positive and gram-negative bacterial strains. None of the compounds showed antifungal activity against yeast-like fungi.
Highly Stereoselective And Efficient Synthesis Of The Dopa Analogue In Pepticinnamin E Via Enantioselective Hydrogenation Of Dehydroamino Acids, Dequn Sun
Turkish Journal of Chemistry
An efficient and new method was developed to prepare the dopa analogue 11 in natural pepticinnamin via catalytic hydrogenation of dehydroamino acids (DDAA) with a good yield and ee. Product 11 is a key intermediate towards the total synthesis of pepticinnamin E and its analogues.
Synthesis And Antimicrobial Activity Of N-Alkyl Substituted P-Methyl (E)-3- And 4-Azachalconium Bromides, Nuretti̇n Yayli, Gülbi̇n Misir, Nuran Yayli, Ahmet Yaşar, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ
Synthesis And Antimicrobial Activity Of N-Alkyl Substituted P-Methyl (E)-3- And 4-Azachalconium Bromides, Nuretti̇n Yayli, Gülbi̇n Misir, Nuran Yayli, Ahmet Yaşar, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ
Turkish Journal of Chemistry
Twenty new N-alkyl substituted p-methyl (E)-3- and 4-azachalcones (1a-j, 2a-j){3-[(1E)-3-(4-methylp-henyl)-3- oxoprop-1-en-1-yl]-1-alkyl (C_{5-12,_{14-15) pyridinium bromides (1a-j) and 4-[(1E)-3-(4-methylp-henyl)-3-oxoprop-1-en-1-yl]-1-alkyl (C_{5-12,_{14-15) pyridinium bromides (2a-j)} were synthesized and tested for antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Enterococcus faecalis, Proteus vulgaris, and Escherichia coli. They showed good antimicrobial activity especially against the gram-positive bacteria tested with minimal inhibitory concentration (MIC) values less than 4.7 \mu g/mL in most cases. The optimum length of the alkyl chain for better and broader activity is situated in the range of 8-12 carbon atoms in the series of compounds 1a-j, 2a-j. The non-alkylated compounds 1-2 were …
Performance Evaluation Of Platinum-Based Catalysts For The Development Of Proton Exchange Membrane Fuel Cells, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza
Performance Evaluation Of Platinum-Based Catalysts For The Development Of Proton Exchange Membrane Fuel Cells, Abdul Sattar Ali Khan, Riaz Ahmed, Muhammad Latif Mirza
Turkish Journal of Chemistry
Platinum-based catalysts are considered the most efficient catalysts for triggering electrochemical reactions in proton exchange membrane (PEM) fuel cells. In the present study, commercial catalysts containing 10% and 30% Pt supported on Vulcan XC-72 carbon were studied to assess their performance in PEM fuel cells. Both catalysts consisted of Pt particles of almost the same size. The utility of these catalysts in PEM fuel cells was studied by finding the real surface area and rate of electro-oxidation of methanol in 0.5 M H_2SO_4 by using cyclic voltammetry. The methanol oxidation reaction was used for characterization of catalysts of PEM fuel …
Synthesis, Structural Determination, And Biological Activity Of New 7-Hydroxy-3-Pyrazolyl-4h-Chromen- 4-Ones And Their O-\Beta-D-Glucosides, Kishor Hatzade, Vijay Taile, Pravin Gaidhane, Vishwas Ingle
Synthesis, Structural Determination, And Biological Activity Of New 7-Hydroxy-3-Pyrazolyl-4h-Chromen- 4-Ones And Their O-\Beta-D-Glucosides, Kishor Hatzade, Vijay Taile, Pravin Gaidhane, Vishwas Ingle
Turkish Journal of Chemistry
A convenient route to synthesize some new medicinally important 7-hydroxy-3-pyrazolyl chromones (3a-i) is described. The interaction of 7-hydroxy-3-formyl chromone (1) with various substituted acetophenones and further cyclization with hydrazine hydrate in an aprotic solvent followed by condensation with 2, 3, 4, 6-tetra-o-acetyl-\alpha-dglucopyranosyl bromide afforded 2, 3, 4, 6-tetra-o-acetyl-\beta-d-glucopyranosyloxy-3-(3-aryl-1H-pyrazol-5- yl)-4H-chromen-4-ones (4a-i). Later deacetylation with anhydrous zinc acetate in methanol gave 7-o-\beta-d-glucopyranosyloxy-3-(3-aryl- 1H-pyrazol-5-yl)-4H-chromen-4-ones (5a-i). These compounds were evaluated for their in vitro antimicrobial and anti-oxidant activity. The structures of these newly synthesized o-glucosides were established by IR, NMR, mass spectra, elemental analysis, and chemical analysis.