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Articles 31 - 60 of 91
Full-Text Articles in Physical Sciences and Mathematics
Reactivity Of The 2-Aryl-6,8-Dibromo-2,3-Dihydroquinolin-4(1$H)$-Ones In A Palladium Catalyzed Sonogashira Cross-Coupling Reaction, Malose Jack Mphahlele, Felix Adetunji Oyeyiola
Reactivity Of The 2-Aryl-6,8-Dibromo-2,3-Dihydroquinolin-4(1$H)$-Ones In A Palladium Catalyzed Sonogashira Cross-Coupling Reaction, Malose Jack Mphahlele, Felix Adetunji Oyeyiola
Turkish Journal of Chemistry
Pd/C-PPh$_{3}$--CuI catalyzed Sonogashira cross-coupling of the 2-aryl-6,8-dibromo-2,3-dihydroquinolin-4(1$H)$-ones with phenyl acetylene or 3-butyn-1-ol afforded the corresponding 8-alkynylated quinolin-4(1$H)$-one derivatives, exclusively. Double carbo-substitution to afford the 6,8-dialkynyl derivatives was observed when PdCl$_{2}$(PPh$_{3})_{2}$ was used as Pd(0) source. The monoalkynylated derivatives were, in turn, subjected to PdCl$_{2}$ in acetonitrile under reflux to afford either the corresponding 2,4-diaryl-8-bromopyrrolo[3,2,1-\textit{ij}]quinolinones or the 8-(4-hydroxybutanoyl)-substituted quinolinone derivatives, exclusively. Suzuki--Miyaura cross-coupling of the 2-aryl-6-bromo-8-(alkynyl)quinolin-4-ones afforded the 2,4,8-trisubstituted pyrrolo[3,2,1-\textit{ij}]quinolin-6-ones.
Synthesis Of Novel 1,2,4-Triazoles And Triazolo-Thiadiazines As Anticancer Agents, Thoraya Abd El-Reheem Farghaly, Magda Ahmad Abdallah, Huda Kamel Mmahmoud
Synthesis Of Novel 1,2,4-Triazoles And Triazolo-Thiadiazines As Anticancer Agents, Thoraya Abd El-Reheem Farghaly, Magda Ahmad Abdallah, Huda Kamel Mmahmoud
Turkish Journal of Chemistry
A new series of 7-arylazo-5$H$-3-(trifluoromethyl)-6-methyl-1,2,4-triazolo-[3,4-$b$]-1,3,4-thiadiazines was prepared by reaction of 4-amino-3-trifluoromethyl-5-mercapto-1,2,4-triazoles with $N$-aryl-2-oxo-propane hydrazonoyl chloride in dioxane under reflux in the presence of triethylamine. Furthermore, Schiff bases of 4-amino-5-mercapto-1,2,4-triazole derivatives were reacted with a variety of hydrazonoyl chlorides and gave the respective hydrazonothioates. In addition, the novel \textit{bis}-(1,2,4-triazole-3-thione) was reacted with the appropriate hydrazonoyl chloride in dioxane under reflux in the presence of triethylamine to give the corresponding \textit{bis}-(1,2,4-triazolethiohydrazonoate). The structures of the new compounds were established based on elemental and spectral data. The mechanism of the studied reaction was also discussed. Moreover, some of the new products were screened …
Synthesis Of Novel Triazoles Bearing 1,2,4-Oxadiazole And Phenylsulfonyl Groups By 1,3-Dipolar Cycloaddition Of Some Organic Azides And Their Biological Activities, Yaşar Dürüst, Hamza Karakuş, Muhsi̇ne Zeynep Yavuz, Ali̇ Akçahan Gepdi̇remen
Synthesis Of Novel Triazoles Bearing 1,2,4-Oxadiazole And Phenylsulfonyl Groups By 1,3-Dipolar Cycloaddition Of Some Organic Azides And Their Biological Activities, Yaşar Dürüst, Hamza Karakuş, Muhsi̇ne Zeynep Yavuz, Ali̇ Akçahan Gepdi̇remen
Turkish Journal of Chemistry
1,3-Dipolar cycloaddition of 5-azidomethyl-3-p-substituted phenyl-1,2,4-oxadiazoles to phenyl vinyl sulfone and bismaleimide gives rise straightforwardly to 1-((3-(p-substituted) phenyl-1,2,4-oxadiazol-5-yl)methyl)-4-(phenylsul\-fonyl)-4,5-dihydro-1H-1,2,3-triazoles and bisdihydropyrrolo[3,4-d][1,2,3]triazole-4,6(3aH,5H)-diones. The structures of the new cycloadducts were elucidated by means of IR, NMR (^1H, ^{13}C, 2D), mass spectra, and physical characteristics (mp and R_f values). In addition, anticancer activities of the cycloadducts against MCF-7 cells were also investigated.
Synthesis And Characterization Of A Novel 3-Amino-1,2,4-Triazole Lead(Ii) Coordination Polymer, Şebnem Esen Sözerli̇, Arzu Özen, İbrahi̇m Kani̇, Deni̇z Demi̇r
Synthesis And Characterization Of A Novel 3-Amino-1,2,4-Triazole Lead(Ii) Coordination Polymer, Şebnem Esen Sözerli̇, Arzu Özen, İbrahi̇m Kani̇, Deni̇z Demi̇r
Turkish Journal of Chemistry
A novel [Pb_2(\mu-atrz)_2(\mu-CH_3COO)(CH_3COO)]_n (atrz = 3-amino-1,2,4-triazole) complex was synthesized and characterized by IR spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The molecular structure shows that the complex is a coordination polymer in which there are 2 different lead(II) ions with coordination number of 5, Pb(2), and, with a coordination number of 4, Pb(1). Each atrz acts as a bridging ligand between 2 Pb(II) ions through the 2 adjacent nitrogen atoms of the triazole ring. The acetate anions show different types of coordination mode: one acts as a bridge by coordination of the same oxygen atom with Pb(II) ions and …
Electrochemistry Of 2,6-Diaminopurine On Multiwall Carbon Nanotube Modified Glassy Carbon Electrode, Ebru Mavi̇oğlu Ayan, Şükri̇ye Karabi̇beroğlu, Zekerya Dursun
Electrochemistry Of 2,6-Diaminopurine On Multiwall Carbon Nanotube Modified Glassy Carbon Electrode, Ebru Mavi̇oğlu Ayan, Şükri̇ye Karabi̇beroğlu, Zekerya Dursun
Turkish Journal of Chemistry
The electrochemical oxidation of 2,6-diaminopurine (2,6-DAP) was studied in pH 7.4 phosphate buffer solution on multiwall carbon nanotube modified glassy carbon electrode (MWCNT/GCE) over a temperature range of 20 to 50 °C using cyclic voltammetry. 2,6-DAP oxidation on MWCNT/GCE showed a well-defined and irreversible oxidation peak at about 0.72 V vs. Ag/AgCl at pH 7.4. The oxidation potential of 2,6-DAP linearly varied with pH over the range of 3.0 to 10.0 with a slope of --0.0547 V/pH, implying that 2 protons were accompanied by 2 electrons transferred in the electrochemical reaction. The activation energy, Ea, of oxidation reaction was found …
Synthesis And Biological Activities Of Methylenebis-4h-1,2,4-Triazole Derivatives, Yildiz Uygun, Hacer Bayrak, Havva Özkan
Synthesis And Biological Activities Of Methylenebis-4h-1,2,4-Triazole Derivatives, Yildiz Uygun, Hacer Bayrak, Havva Özkan
Turkish Journal of Chemistry
5,5'-Methylenebis(4--phenyl-4H-1,2,4-triazole-3-thiol) (2) was synthesized starting from hydrazinecarbothioamide compound (1). Treatment of compound 2 with ethyl bromoacetate produced diethyl 5,5'-{methylenebis[(4-phenyl-4H-1,2,4-triazole-5,3-diyl)thio]}diacetate (3), which was converted to the corresponding diacetohydrazide derivative (4) by treatment with hydrazine hydrate. The reaction of compound 4 with several aldehydes produced the corresponding arylidene hydrazides, 5a--d. Syntheses of Mannich bases 6a--c were carried out by the treatment of compound 2 with several amines in the presence of formaldehyde. (4{[5-({5-[(4-Amino-2-chlorophenyl)thio]-4-phenyl-4H-1,2,4-triazol-3-ylmethyl)-4-phenyl-4H-1,2,4-triazol-3-yl]thio}-3-chlorophenyl)amine (8) was prepared by reduction of 2 nitro groups of 3,3' -methylenebis{5-[(2-chloro-4-nitrophenyl)thio]-4-phenyl-4H-1,2,4-triazole} (7) that were obtained from the condensation of 2} with 3,4-dichloronitrobenzene. The newly synthesized compounds were screened …
Syntheses, Characterization, And Antibacterial Study Of Titanium Complexes, Raj Kaushal, Nitesh Kumar, Pamita Awasthi, Kiran Nehra
Syntheses, Characterization, And Antibacterial Study Of Titanium Complexes, Raj Kaushal, Nitesh Kumar, Pamita Awasthi, Kiran Nehra
Turkish Journal of Chemistry
Titanium(II) complexes of composition TiCl_2(L)_2 [where L = 2,2'-bipyridine (bipy), 4,4'-dimethyl-2,2'-bipyridine (bpMe), 4,4'-dimethoxy-2,2'-bipyridine (bpoMe), 6,6'-dimethyl-2,2'-bipyridine (dpMe), adamantylamine (ada)] were prepared by reacting titanium tetrachloride and N-containing bulky ligands in predetermined molar ratios. The complexes synthesized were characterized by different spectroscopic techniques, viz. UV-visible, FTIR, ^1H NMR, and mass spectrometry. The stoichiometry of the complexes was established by their elemental analysis (chlorine and titanium estimation). The unit cell parameters calculated by using the powder XRD tool confirm the monoclinic unit system and P lattice type for all complexes. Antibacterial screening of the ligands as well as the complexes was carried out …
Synthesis, Characterization, And Luminescence Of Zinc(Ii) And Cadmium(Ii) Coordination Complexes: [Zn(Phen)_2(Ch_3coo)](Clo_4), [Zn(Bpy)_2(Clo_4)](Clo_4), And [Cd(Phen)_2(No_3)_2], İbrahi̇m Kani̇, Mehmet Kurtça
Synthesis, Characterization, And Luminescence Of Zinc(Ii) And Cadmium(Ii) Coordination Complexes: [Zn(Phen)_2(Ch_3coo)](Clo_4), [Zn(Bpy)_2(Clo_4)](Clo_4), And [Cd(Phen)_2(No_3)_2], İbrahi̇m Kani̇, Mehmet Kurtça
Turkish Journal of Chemistry
Three metal complexes, [Zn(phen)_2(CH_3COO)](ClO_4) (1), [Zn(bpy)_2(ClO_4)](ClO_4) (2), and [Cd(phen)_2 (NO_3)_2] (3) (phen = 1,10-phenanthroline, bpy = 2,2 {Abedini, 2005 #222} -bipyridine), were synthesized and their structures were determined by single-crystal X-ray diffraction analyses. In 1, Zn(II) is coordinated by 4 nitrogen atoms from 2 phen molecules and 2 oxygen atoms from 1 acetato to form an octahedral configuration. In 2, Zn(II) has pentacoordination geometry with chelating 2 bpy and 1 perchlorato ion. In 3, phen and NO_3^- serve as bidentate ligands coordinating to Cd(II) through their nitrogen and oxygen atoms to form 8 coordination. Three-dimensional frameworks of complexes 1--3 are …
Polymers From Renewable Resources: Synthesis And Characterization Of Poly(2,5-Dihydro-2,5-Dimethoxy Furan), Hakan Çi̇ftçi̇, Zeki̇ Öktem, Hasan Nur Testereci̇
Polymers From Renewable Resources: Synthesis And Characterization Of Poly(2,5-Dihydro-2,5-Dimethoxy Furan), Hakan Çi̇ftçi̇, Zeki̇ Öktem, Hasan Nur Testereci̇
Turkish Journal of Chemistry
The cationic polymerization of cis, trans-2,5-dihydro-2,5-dimethoxy furan (DHMF) was studied in the presence of HClO_4, in acetonitrile. Different reaction parameters were investigated such as initiator concentration and temperature with duration. Obtained polymers were soluble in dimethylsulfoxide (DMSO) and dimethylformamide (DMF) and the M_n value was calculated as 2700 g/mol by cryoscopy. The FT-IR and ^1H-NMR results indicate that the polymerization proceeds via ring opening. Thermal properties were studied by DSC and TGA.
Preparation And Antimicrobial Activity Evaluation Of Some Quinoline Derivatives Containing An Azole Nucleus, Muhammet Özyanik, Serpi̇l Demi̇rci̇, Hakan Bektaş, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Şengül Alpay Karaoğlu
Preparation And Antimicrobial Activity Evaluation Of Some Quinoline Derivatives Containing An Azole Nucleus, Muhammet Özyanik, Serpi̇l Demi̇rci̇, Hakan Bektaş, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
Quinoline-2-carbohydrazide (2) obtained from quinaldic acid (1) was converted to the corresponding carbothioamide 3 and carboxamide 6 by treatment with benzyliso(thio)cyanate. The basic treatment of 3 and 6 yielded the corresponding 1,2,4-triazole derivatives 4 and 7. The synthesis of 5-(quinolin-2-yl)-1,3,4- oxadiazol-2-thiol (9) was performed from the reaction of 1 with CS_2 in basic media. The Mannich reaction of compounds 4, 7, and 9 resulted in the formation of aminoalkylated derivatives 5a-c, 8, and 10a,b. The condensation of 1 with thiosemicarbazide, carbohydrazide, or thiocarbohydrazide gave the corresponding 1,2,4-triazole derivatives (11-13). The treatment of 4-amino-5-(quinolin-2-yl)- 4H-1,2,4-triazole-3-thiol (13) with 4-chlorophenacyl bromide caused the …
Synthesis, Characterization, And Antioxidant Activities Of New Trisubstituted Triazoles, Kemal Sancak, Yasemi̇n Ünver, Di̇lek Ünlüer, Esra Düğdü, Gülcan Kör, Fati̇h Çeli̇k, Emrah Bi̇ri̇nci̇
Synthesis, Characterization, And Antioxidant Activities Of New Trisubstituted Triazoles, Kemal Sancak, Yasemi̇n Ünver, Di̇lek Ünlüer, Esra Düğdü, Gülcan Kör, Fati̇h Çeli̇k, Emrah Bi̇ri̇nci̇
Turkish Journal of Chemistry
A series of new 4-(3,4dimethoxyphenethyl)-3,5-akyl/aryl-4H- 1,2,4-triazoles (3a-g) were obtained by reaction of ethyl N'-(alkylidene/arylidene)hydrazonate (1) and 2-(3,4-dimethoxy phenyl)ethanamine (2). Compounds 4d, e, and g were synthesized from the reaction of corresponding compounds 3d, e, and g with BBr_3, respectively. The 10 new compounds synthesized were characterized by elemental analyses, IR, ^1H-NMR, and ^{13}C-NMR spectral data. The structure of compound 3g was inferred through IR, ^1H-, ^{13}C-NMR, elemental analyses, and X-ray spectral techniques. In addition, the newly synthesized chemicals were screened for their antioxidant properties. Among the chemicals tested, 4d, e, and g exhibited the highest degree of antioxidant activity.
Determination Of Ultratrace Amounts Of Dichloro-Nitrobenzene And Dichloro-Nitroaniline In Water Samples Using Solidified Floating Organic Drop Microextraction (Sfodme) And Gas Chromatography, Shayessteh Dadfarnia, Mohammad Mirzaei, Ali Mohammad Haji Shabani, Batoul Ramazanzadeh
Determination Of Ultratrace Amounts Of Dichloro-Nitrobenzene And Dichloro-Nitroaniline In Water Samples Using Solidified Floating Organic Drop Microextraction (Sfodme) And Gas Chromatography, Shayessteh Dadfarnia, Mohammad Mirzaei, Ali Mohammad Haji Shabani, Batoul Ramazanzadeh
Turkish Journal of Chemistry
Solidified floating organic drop microextraction (SFODME) in combination with gas chromatography with an electron capture detector was used for separation/enrichment and determination of 2,5-dichloro-nitrobenzene, 2,3-dichloro-nitrobenzene, and 2,6-dichloro-4-nitroaniline in water samples. The main parameters affecting the performance of SFOME, such as solvent volume, extraction time, stirring rate, extraction temperature, sample volume, nature of the solvent and ionic strength were optimized. Under the optimum experimental conditions, good relative standard deviations of 7.5%, 6.9%, and 9.3% for 7 extractions and determination of 50 ng L^{-1} of 2,5-dichloro-nitrobenzene, 2,3-dichloro-nitrobenzene and 2,6-dichloro-4-nitroaniline were obtained, respectively. Enrichment factors of 1390, 1398, and 1362 and detection limits …
Reduction, Mannich Reaction And Antimicrobial Activity Evaluation Of Some New 1,2,4-Triazol-3-One Derivatives, Seda Fandakli, Serap Başoğlu, Hakan Bektaş, Meltem Yolal, Ahmet Demi̇rbaş, Şengül Alpay Karaoğlu
Reduction, Mannich Reaction And Antimicrobial Activity Evaluation Of Some New 1,2,4-Triazol-3-One Derivatives, Seda Fandakli, Serap Başoğlu, Hakan Bektaş, Meltem Yolal, Ahmet Demi̇rbaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
Ethyl[4-arylmethyleneamino-3-(4-metylphenyl)-5-oxo-4,5-dihydro- 1H-1,2,4-triazole-1-yl]acetates (3a-e and 10a-d) were obtained starting from 4-amino-2,4-dihydro-3H-1,2,4-triazol-3-ones (1 and 9) in 2 steps. The treatment of 3a-e with NaBH_4 resulted in the formation of 3 kinds of product incorporating carboxcilic acid (4a-c) or alcohol (5a-e) functionality. [4-{[(4-Methoxyphenyl)methylene]amino}- and 4-{[pyridin-4-ylmethylene]amino}-3-(4-methylphenyl)-5-oxo-4,5-dihydro-1H- 1,2,4-triazole-1-yl] acetic acids (6a, 6e) were obtained by the hydrolysis of the corresponding esters (5a-5e). The treatment of 6a with NaBH_4 caused the reduction of only the imine bond; the carboxyl group remained unchanged. Then this carboxylic acid was converted to the corresponding hydrazide (8) in 2 steps by reaction with ethanol and hydrazine hydrate, respectively. The synthesis …
Synthesis, Structural Characterization, And Benzyl Alcohol Oxidation Activity Of Mononuclear Manganese(Ii) Complex With 2,2'-Bipyridine: [Mn(Bipy)_2(Clo_4)_2], İbrahi̇m Kani̇, Mehmet Kurtça
Synthesis, Structural Characterization, And Benzyl Alcohol Oxidation Activity Of Mononuclear Manganese(Ii) Complex With 2,2'-Bipyridine: [Mn(Bipy)_2(Clo_4)_2], İbrahi̇m Kani̇, Mehmet Kurtça
Turkish Journal of Chemistry
A manganese(II) complex of 2,2'-bipyridine (bipy) was synthesized and characterized by X-ray diffraction, IR, and UV-vis spectroscopy. The activity of the complex was tested for oxidation of benzyl alcohols using t-BuOOH as an oxidant in organic solvents and in an organic/water biphasic system (hexane/H_2O, toluene/H_2O). The effect of solvent, temperature, oxidant, and some additives (KBr, N(C_4H_9)Br, and N-bromosuccinimide) on the oxidation of benzyl alcohol is reported. The results show that benzyl alcohol was selectively converted to benzaldehyde in 71.9% yield within 4 h in acetonitrile. Control experiments performed without catalyst and the corresponding metal salt as catalyst produced no benzaldehyde …
Synthesis Of Linezolid-Like Molecules And Evaluation Of Their Antimicrobial Activities, Serap Başoğlu, Meltem Yolal, Ahmet Demi̇rbaş, Hakan Bektaş, Rza Abbasoğlu, Nesli̇han Demi̇rbaş
Synthesis Of Linezolid-Like Molecules And Evaluation Of Their Antimicrobial Activities, Serap Başoğlu, Meltem Yolal, Ahmet Demi̇rbaş, Hakan Bektaş, Rza Abbasoğlu, Nesli̇han Demi̇rbaş
Turkish Journal of Chemistry
3-Fluoro-4-(morpholin-4-yl)aniline (2), prepared from 3,4-difluoronitrobenzene, was converted to the corresponding Schiff base (3) by treatment with indol-3-carbaldehyde. The treatment of thiourea 4 and carbothioamide derivatives 9 with ethyl bromoacetate or 4-substituted phenacyl bromides generated the corresponding thiazolidinone (5 and 13) and thiazoline (6 and 12) derivatives, respectively. The acidic or basic treatment of carbothioamide 9 produced 1,3,4-thiadiazole (11) or 1,2,4-triazole (10) compounds, respectively. The structural assignments of the new compounds were based on elemental analysis and spectral (IR, ^1H-NMR, ^{13}C-NMR, and LC-MS) data. The antimicrobial activity study revealed that all compounds showed good antitubercular activities.
Design And Synthesis Of New 1,2,4-Triazole Derivatives Containing Morpholine Moiety As Antimicrobial Agents, Deni̇z Şahi̇n, Hacer Bayrak, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Design And Synthesis Of New 1,2,4-Triazole Derivatives Containing Morpholine Moiety As Antimicrobial Agents, Deni̇z Şahi̇n, Hacer Bayrak, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
2-Morpholine-4ylethyl-3H-1,2,4-triazole-3-ones (2a, 2b) were obtained from the condensation between the corresponding ethoxycarbonylhydrazones and 2-morpholinoethanamine. 2a was converted to acetohydrazide (4) via the formation of an ester derivative (3). Treatment of 2a and 2b with several aryl sulfonyl chlorides afforded the corresponding 2-arylsulfonyl-1,2,4-triazole-3-ones (5a-c and 6). The reaction of hydrazide (4) with benzyl iso- and benzyl isothiocyanate produced the corresponding carboxamide (8a) and carbothioamide (8b). The basic treatment of 8b yielded 5-mercapto-4H-1,2,4-triazol-3-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one (10). The synthesis of 1,3-thiazol-2(3H)-ylidene-1,2,4-triazol-1- ylacetohydrazide (11) and 1,3-oxazole-2(3H)-ylidene-1,2,4-triazole- 1-yl)acetohydrazide (9) derivatives was performed from the reaction of 8a and 8b with substituted phenacyl bromides. All the newly synthesized …
Synthesis And Antioxidant And Antimicrobial Evaluation Of Novel 4-Substituted-1h-1,2,4-Triazole Derivatives, Sultan Baytaş, Evi̇n Kapçak, Tülay Çoban, Hati̇ce Özbi̇lge
Synthesis And Antioxidant And Antimicrobial Evaluation Of Novel 4-Substituted-1h-1,2,4-Triazole Derivatives, Sultan Baytaş, Evi̇n Kapçak, Tülay Çoban, Hati̇ce Özbi̇lge
Turkish Journal of Chemistry
A series of 4-benzyl/phenyl-3-(1-methyl-1H-indole-2-yl)-1H- 1,2,4-triazole-5(4H)-thione (4a,b) and 2-{4-[benzyl/phenyl-5- (substitutedbenzylthio)]-4H-1,2,4-triazole-3-yl}-1-methyl-1H-indole derivatives (5a-p) were synthesized and evaluated for their in vitro scavenging of DPPH and superoxide radical, and lipid peroxidation inhibition effects as well as their antimicrobial properties. DPPH radical scavenging capacity was found to be equipotent with BHT and found in compounds containing 1,2,4-triazole-5(4H)-thione moiety (4a,b). With regard to antimicrobial properties, compound 5k showed slight antimicrobial activity against all the test microorganisms.
Simultaneous Determination Of Copper And Cadmium In Environmental Water And Tea Samples By Adsorptive Stripping Voltammetry, Mohammad Bagher Gholivand, Alireza Pourhossein, Mohsen Shahlaei
Simultaneous Determination Of Copper And Cadmium In Environmental Water And Tea Samples By Adsorptive Stripping Voltammetry, Mohammad Bagher Gholivand, Alireza Pourhossein, Mohsen Shahlaei
Turkish Journal of Chemistry
A sensitive and selective method for the simultaneous determination of copper and cadmium in seawater, river water, and tea samples is described. The method is based on the adsorptive accumulation of 2,2--dithiosalicylic acid complexes of these elements onto a hanging mercury drop electrode, followed by reduction of adsorbed species by voltammetric scan using differential pulse modulation. Optimal analytical conditions were as follows: ligand concentration of 11 nM, pH of 9.5, and an adsorption potential at --300 mV versus Ag/AgCl, with an accumulation time of 60 s. The peak currents are proportional to the concentration of copper and cadmium over the …
Synthesis And Characterisation Of Tris(2,4-Dinitrophenoxo)Monooxovanadium(V) And Its Complex Salts, Neeraj Sharma, Reena Sharma, Meena Kumari, Subhash Chaudhry
Synthesis And Characterisation Of Tris(2,4-Dinitrophenoxo)Monooxovanadium(V) And Its Complex Salts, Neeraj Sharma, Reena Sharma, Meena Kumari, Subhash Chaudhry
Turkish Journal of Chemistry
The monooxovanadium(V) complex of composition [VO(OC_6H_3(NO_2)_2-2,4)_3] (I) was synthesized by the reaction of VOCl_3 with Me_3SiOC_6H_3(NO_2)_2-2,4 in toluene and characterised by elemental analyses, molar conductance, and IR, ^1H- and ^{13}C-NMR, and mass spectral studies. The reactions of (I) with alkali metal 2,4-dinitrophenoxides [MOC_6H_3(NO_2)_2-2,4] (M = Li, Na, K) yield complex salts of composition M[VO(OC_6H_3(NO_2)_2-2,4]_4 authenticated by physicochemical and IR spectral studies. Thermal behaviour of complexes was studied by TG and DTA techniques. The molecular modelling calculations of the parent complex and its complex salts were performed to visualise the probable geometry around vanadium metal, which, coupled with spectroscopic evidence, suggests …
A Study Of Behavior Of Some 5-Substituted- 4-Phenyl-1,2,4-Triazoline-3-Thiones In Sulfuric Acid Solution Using Characteristic Vector Analysis, Vesna Dimova
Turkish Journal of Chemistry
The protonation process of 1,2,4-triazoline-3-thiones (T3T) was studied in aqueous sulfuric acid using the UV method. Characteristic vector analysis (CVA) was used to reconstruct the experimentally obtained UV spectra, to overcome difficulties in calculating the protonation constants of T3T, and to separate the effect of protonation from the generalized medium effect. pK_{TH}+ values were calculated using the Hammett acidity function method, the Bunnett and Olsen method, and the excess acidity function method. The obtained values for m, \phi and m* were close to those characteristic for similar thio compounds, indicating that the protonation site in the molecule of T3T is …
Synthesis, Crystal Structure, And Antioxidant Properties Of Novel 1,2,4-Triazol-5-Ones Containing 3,4-Dimethoxyphenyl And 3,4-Dihydroxyphenyl Moiety, Yasemi̇n Ünver, Sevgi̇ Meydanal, Kemal Sancak, Di̇lek Ünlüer, Reşat Ustabaş, Esra Düğdü
Synthesis, Crystal Structure, And Antioxidant Properties Of Novel 1,2,4-Triazol-5-Ones Containing 3,4-Dimethoxyphenyl And 3,4-Dihydroxyphenyl Moiety, Yasemi̇n Ünver, Sevgi̇ Meydanal, Kemal Sancak, Di̇lek Ünlüer, Reşat Ustabaş, Esra Düğdü
Turkish Journal of Chemistry
A series of new 4-(3,4-dimethoxyphenethyl)-5-akyl/aryl-2H- 1,2,4-triazol-3(4H)-ones (3a-g) was obtained by the reaction of ethyl 2-(ethoxy)(alkylidene/arylidene)hydrazinecarboxylate (1) and 2-(3,4-dimethoxyphen- yl)ethanamine (2). Compounds 4a-f and 5 were synthesized from the reaction of corresponding compounds 3a-f and 3g with BBr_3, respectively. With elemental analysis, IR, ^1H-NMR, and ^{13C-NMR spectral data, 14 newly synthesized compounds were characterized. The structure of compound 3a was inferred through IR, ^1H- and ^{13}C-NMR, elemental analysis, and X-ray spectral techniques. In addition, the newly synthesized chemicals were screened for their antioxidant properties. Among the chemicals tested, 4a, 4c, 4d, 4f, and 5 exhibited the highest degree of antioxidant activity.
Synthesis And Anti-Helicobacter Pylori Activity Of (4-Nitro-1-Imidazolylmethyl)-1,2,4-Triazoles, 1,3,4-Thiadiazoles, And 1,3,4-Oxadiazoles, Asal Fallah-Tafti, Tahmineh Akbarzadeh, Parastoo Saniee, Farideh Siavoshi, Abbas Shafiee, Alireza Foroumadi
Synthesis And Anti-Helicobacter Pylori Activity Of (4-Nitro-1-Imidazolylmethyl)-1,2,4-Triazoles, 1,3,4-Thiadiazoles, And 1,3,4-Oxadiazoles, Asal Fallah-Tafti, Tahmineh Akbarzadeh, Parastoo Saniee, Farideh Siavoshi, Abbas Shafiee, Alireza Foroumadi
Turkish Journal of Chemistry
A series of [(4-nitro-1H-imidazol-1-yl)methyl]-1,2,4- triazoles and 1,3,4-thiadiazoles were prepared and evaluated for their activity against sensitive and resistant H. pylori strains. Study of the structure-activity relationship of these series of compounds indicated that the type of nitroimidazole moiety and the pendent group on the heteroaryl analog dramatically impact the anti-H. pylori activity. In triazole series, compound 5d, containing a 4-methyl phenyl group on the triazole ring, was the most potent compound tested against both metronidazole-sensitive and -resistant strains at a concentration of 8 \mu g.
Solid Phase Extraction Of Copper, Nickel, And Cobalt In Water Samples After Extraction Using Surfactant Coated Alumina Modified With Indane-1,2,3-Trione 1,2-Dioxime And Determination By Flame Atomic Absorption Spectrometry, Mahdi Hosseini, Nasser Dalali, Ali Karimi, Kourosh Dastanra
Solid Phase Extraction Of Copper, Nickel, And Cobalt In Water Samples After Extraction Using Surfactant Coated Alumina Modified With Indane-1,2,3-Trione 1,2-Dioxime And Determination By Flame Atomic Absorption Spectrometry, Mahdi Hosseini, Nasser Dalali, Ali Karimi, Kourosh Dastanra
Turkish Journal of Chemistry
A simple method for simultaneous pre-concentration of Cu, Ni, and Co metal ions prior to their determination by flame atomic absorption spectrometry is reported. The method is based on the extraction of target ions via complexation with indane-1,2,3-trione 1,2-dioxime immobilized on sodium dodecyl sulfate (SDS) coated alumina. The metal content on the adsorbent was eluted with 4.5 mL of 2 mol L^{-1} nitric acid. The influences of the analytical parameters including pH, sample volume and flow rate, and eluent type and flow rate were investigated. The effect of matrix ions on the retentions of the analytes was also examined. The …
Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan
Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan
Turkish Journal of Chemistry
Compounds 2 were synthesised via the reaction of 4-amino-5-thiophen-2-yl-methyl-2,4-dihydro-[1,2,4]-triazol-3-one (1) with aldehydes. Compounds 3 and 4 were obtained from compounds 2 with bromo acetophenone and ethyl bromoacetate, respectively. The synthesis of compounds 2, 3, and 4 and crystal structure of compound 2a are being reported. The molecular structures were identified by IR, ^1H-NMR, ^{13}C-NMR, MS, and elemental analyses. Compound 2a crystallises in the monoclinic P 2_1/n space group, with a = 6.565(5) Å, b = 18.278(5) Å, c = 13.8166(18) Å, \beta = 96.227(5)°, V = 1553.6(14) Å^3, Z = 4. The newly compounds synthesised were screened for their antibacterial …
Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal
Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal
Turkish Journal of Chemistry
The acidity constants, relative stabilities, and tautomeric equilibrium constants of some 1,2,4-triazole derivatives were determined using the density functional theory (DFT) with the B3LYP method and 6-311G(d,p) basis set. The integral equation formalism version of the polarizable continuum model (IEFPCM) was used in the calculations of the aqueous phase. The calculated tautomeric equilibrium and relative stabilities values revealed that the 4H-1,2,4 triazole form for all studied molecules was favored over the 1H-1,2,4 triazole form. Protonation processes indicated the predominance of the 1H-1,2,4 triazole form over the 2H-1,2,4 triazole form. The correlation attempt between the experimental and the calculated acidity constants, …
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.
Synthesis And Antimicrobial Activities Of 2-(5-Mercapto)-1,3-Oxadiazol-2-Ylmethyl-1,2,4-Triazol-3-One Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hakan Bektaş, Şengül Alpay Karaoğlu, Deni̇z Şahi̇n
Synthesis And Antimicrobial Activities Of 2-(5-Mercapto)-1,3-Oxadiazol-2-Ylmethyl-1,2,4-Triazol-3-One Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hakan Bektaş, Şengül Alpay Karaoğlu, Deni̇z Şahi̇n
Turkish Journal of Chemistry
The synthesis of 4-amino-2-[(5-mercapto-1,3,4-oxadiazol-2- yl)methyl]-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (2) and 4-amino-2-[(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)methyl]- 5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (5) was performed starting from 2-[4-amino-3-(4-methylphenyl)-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl]acetohydrazide (1). The treatment of 2 and 5 with 4-fluorobenzaldehyde (for 8) or salicylaldehyde (for 6) afforded the corresponding Schiff bases (6 and 8). The condensation of 5 with phenacyl bromide produced 4-amino-5-(4-methylphenyl)-2- [(6-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)methyl]- 2,4-dihydro-3H-1,2,4-triazol-3-one (7). The alkylation of 2 and 8 was carried out by using methyl iodide in basic media. Compounds 3 and 10a,b were prepared by aminoalkylation of 2 and 8 with 4-fluorophenyl piperazine, morpholine, or 4-methyl piperazine in the presence of formaldehyde. The synthesized compounds were screened for their antimicrobial activities …
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 …
Synthesis And Characterization Of Novel Triazol Compounds Containing A Thiophen Ring As Potential Antifungal Agents And The Structure Of 2-(2-Hydroxy-2-P-Tolyethyl)-5-(Thiophen-2-Ylmethyl)- 4-(4h-1,2,4-Triazol-4-Yl)-2h-1,2,4-Triazol-3(4h)-One, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Reşat Ustabaş
Synthesis And Characterization Of Novel Triazol Compounds Containing A Thiophen Ring As Potential Antifungal Agents And The Structure Of 2-(2-Hydroxy-2-P-Tolyethyl)-5-(Thiophen-2-Ylmethyl)- 4-(4h-1,2,4-Triazol-4-Yl)-2h-1,2,4-Triazol-3(4h)-One, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Reşat Ustabaş
Turkish Journal of Chemistry
A series of new 4-(3,5-disubstitue-4H-1,2,4-triazol-4-yl)- 5-(thiophen-2-yl-methyl)-2H-1,2,4-triazol-3(4H)-ones (3a-c) were obtained by reaction N'-1-ethoxy-2-thiophen-2-yl-ethylydene hydrazino carboxylic acid ethyl ester (1) and 4-amino-4H-1,2,4-triazoles (2). 4-(3,5-disubstitue-4H-1,2,4-triazol-4-yl)-2-(2-oxo-2-arylethyl)-5- (thiophen-2-yl-methyl)-2H-1,2,4-triazol-3(4H)-ones (4a-e) and ethyl 2-(4-(3,5-disubstitue-4H-1,2,4-triazol-4-yl)-5-oxo-3-(thiophen-2-ylmethyl)- 4,5-dihydro-1,2,4-triazol-1-yl)acetates (6a-c) were obtained by reaction of compounds 3 and bromoacetophenon derivatives and bromo ethylacetate, respectively. Compounds 5a-e were synthesized from the reaction of corresponding compounds 4a-e with NaBH_4. Compounds 7a-c were obtained by the reaction compounds 6 and LiAlH_4. Seventeen new compounds were synthesized and characterized by elemental analyses, IR, ^1H-NMR, and ^{13}C-NMR spectral data. The structure of compound 5d was inferred through IR, ^1H-, ^{13}C-NMR, elemental analyses, and X-ray spectral techniques. …
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
The synthesis of ethyl [3-(cyanomethyl)-5-alkyl-4H-1,2,4-triazol- 4-yl]carbamates (2a-d) was performed starting from ethyl 2-[ethoxy(4- (aryl)methylene]hydrazinecarboxylates (1a, 1b). The treatment of 2a with thiosemicarbazide afforded ethyl [3-[(5-amino-1,3,4-thiadiazol- 2-yl)methyl]-5-(4-nitrophenyl)-4H-1,2,4-triazol-4-yl]carbamates (3a), whereas compound 2b produced 5-{[4-amino-5-(4-methylphenyl)- 4H-1,2,4-triazol-3-yl]methyl}-1,3,4-thiadiazol-2-amine (3b) in the same reaction conditions. The treatment of tert-butyl 2-[2-(4-chlorophenyl)-1-ethoxyethylidene]hydrazinecarboxylate (5) with malonohydrazide or cyanoacethydrazide gave the corresponding 1,2,4-triazol-ylcarbamate derivatives (6 or 9); then the hydrolysis of these compounds resulted in the formation of 3-{[4-amino-5-(4- chlorobenzyl)-4H-1,2,4-triazol-3-yl]methyl}-5-(4-chlorobenzyl)-4H- 1,2,4-triazol-4-amine (7) and [4-amino-5-(4-chlorobenzyl)-4H- 1,2,4-triazole-3-yl]acetonitrile (10), respectively. The synthesis of the Schiff base derivatives 3-(4-chlorobenzyl)-5-{[5-(4-chloroben- zyl)-4-[(2-hydroxyphenyl-methylene)amino]-4H-1,2,4-triazol-3-yl]methyl} -N-(2-hydroxyphenylmethylene)-4H-1,2,4-triazol-4-amine (8), and (5-(4-chlorobenzyl)-4-{[(2,6-dichlorophenyl)methylene]amino}-4H-1,2,4- triazol-3-yl)acetonitrile (12) was performed from the reaction of compounds 7 …