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Articles 121 - 150 of 165

Full-Text Articles in Chemistry

Synthesis, Characterization, And Optical Properties Of Novel 2,5-Bis[4-(2-(-Arylvinyl)Phenyl]-1,3,4-Oxadiazoles, Dao-Hang He, Yong-Chuang Zhu, Zhuo-Ru Yang, Ai-Xi Hu, Gao Cao Jan 2009

Synthesis, Characterization, And Optical Properties Of Novel 2,5-Bis[4-(2-(-Arylvinyl)Phenyl]-1,3,4-Oxadiazoles, Dao-Hang He, Yong-Chuang Zhu, Zhuo-Ru Yang, Ai-Xi Hu, Gao Cao

Turkish Journal of Chemistry

Six novel 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles were synthesized by introducing 1,3,4-oxadiazole moiety into the stilbene skeleton. The synthesis route included the cyclization of p-toluic acid and hydrazine hydrate catalyzed by polyphosphoric acid (PPA), bromination of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), esterification, and the Wittig-Horner reaction. All the title compounds were characterized by ^1H-NMR, MS, and elemental analysis. UV-Vis absorption and fluorescence emission spectra in THF solution were investigated; the compounds may have potential for use in organic optical materials.

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A Convenient Synthesis Of 2-Azido And 2-Thiocyanato-2,3-Unsaturated Cyclic Ketones, Mesut Boz, Ömer Zai̇m, Hi̇lal Esen Jan 2009

A Convenient Synthesis Of 2-Azido And 2-Thiocyanato-2,3-Unsaturated Cyclic Ketones, Mesut Boz, Ömer Zai̇m, Hi̇lal Esen

Turkish Journal of Chemistry

2-Azido and 2-thiocyanato-2,3-unsaturated ketones were synthesized by utilizing functionalization of 5- or 6-membered cycloalkane-1,2-diones, namely diosphenols, with dimethylthiocarbomoyl chloride, which activates the system towards reaction with nucleophiles in acidic conditions. Replacement of the enolic oxygen of the diosphenols with azide and thiocyanate may be achieved by treating their dimethylthiocarbamates with sodium azide or potassium thiocyanate in boiling acetonitrile/acetic acid.

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Synthesis And In Vitro Anti-Helicobacter Pylori Activity Of 2-(Substituted Benzylthio)-5-(5-Nitro-2- Furyl)-1, 3, 4-Thiadiazole Derivatives, Hossein Nasr Isfahani, Khalil Faghihi, Atena Izadkhah, Meisam Shabanian Jan 2009

Synthesis And In Vitro Anti-Helicobacter Pylori Activity Of 2-(Substituted Benzylthio)-5-(5-Nitro-2- Furyl)-1, 3, 4-Thiadiazole Derivatives, Hossein Nasr Isfahani, Khalil Faghihi, Atena Izadkhah, Meisam Shabanian

Turkish Journal of Chemistry

Starting from (5-nitrofuran-2-yl)methylene diacetate, a new series of 2-[(substituted benzyl)thio]-5-(5-nitro-2-furyl)-1,3,4-thiadiazoles (6a-n) were synthesized and the structures of the compounds were determined using spectroscopic methods including mass spectrometry, ^1H-nuclear magnetic resonance, infrared spectroscopy, and elemental analysis. The in vitro anti-Helicobacter pylori activity of the synthesized compounds was evaluated by the disk diffusion method against the clinical isolates of Helicobacter pylori. The results indicated that most of the synthesized compounds exhibited significant inhibitory activity against H. pylori with respect to standard drug metronidazole. Compound 6l, containing the 2-chloro-6-fluorobenzylthio moiety, was the most potent compound tested.

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Synthesis And In Vitro Anti-Helicobacter Pylori Activity Of 2-(Substituted Benzylthio)-5-(5-Nitro-2- Furyl)-1, 3, 4-Thiadiazole Derivatives, Negar Mohammadhosseini, Ali Asadipor, Bahram Letafat, Mohsen Vosooghi, Farideh Siavoshi, Abbas Shafiee, Alireza Foroumadi Jan 2009

Synthesis And In Vitro Anti-Helicobacter Pylori Activity Of 2-(Substituted Benzylthio)-5-(5-Nitro-2- Furyl)-1, 3, 4-Thiadiazole Derivatives, Negar Mohammadhosseini, Ali Asadipor, Bahram Letafat, Mohsen Vosooghi, Farideh Siavoshi, Abbas Shafiee, Alireza Foroumadi

Turkish Journal of Chemistry

Starting from (5-nitrofuran-2-yl)methylene diacetate, a new series of 2-[(substituted benzyl)thio]-5-(5-nitro-2-furyl)-1,3,4-thiadiazoles (6a-n) were synthesized and the structures of the compounds were determined using spectroscopic methods including mass spectrometry, ^1H-nuclear magnetic resonance, infrared spectroscopy, and elemental analysis. The in vitro anti-Helicobacter pylori activity of the synthesized compounds was evaluated by the disk diffusion method against the clinical isolates of Helicobacter pylori. The results indicated that most of the synthesized compounds exhibited significant inhibitory activity against H. pylori with respect to standard drug metronidazole. Compound 6l, containing the 2-chloro-6-fluorobenzylthio moiety, was the most potent compound tested.

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An Efficient One Pot Synthesis Of 1,4-Dihydropyridines Using Alumina Sulfuric Acid (Asa) Catalyst, Mustafa Arslan, Cüneyt Faydali, Mustafa Zengi̇n, Mustafa Küçüki̇slamoğlu, Hülya Demi̇rhan Jan 2009

An Efficient One Pot Synthesis Of 1,4-Dihydropyridines Using Alumina Sulfuric Acid (Asa) Catalyst, Mustafa Arslan, Cüneyt Faydali, Mustafa Zengi̇n, Mustafa Küçüki̇slamoğlu, Hülya Demi̇rhan

Turkish Journal of Chemistry

An efficient synthetic method for 1,4-dihydropyridines has been developed using 3 or 4 component condensation reactions of aldehydes, 1,3-dicarbonyl compounds, and ammonium acetate in the presence of alumina sulfuric acid catalyst in minimum methanol at reflux temperature. This procedure offers several advantages including high yields, an environmentally friendly procedure, short reaction times, and a simple work-up procedure.

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Design, Synthesis, And Characterization Of Novel Hydrophilic Fluorene-Based Derivatives For Bioimaging Applications, Dao Nguyen Jan 2009

Design, Synthesis, And Characterization Of Novel Hydrophilic Fluorene-Based Derivatives For Bioimaging Applications, Dao Nguyen

Electronic Theses and Dissertations

In this work, hydrophilic fluorene-based derivatives that contain ethylene oxide substituents, have been synthesized and characterized for potential use as new fluorophores for bioimaging applications and for fluorescence sensing of heavy metals. Symmetrical and unsymmetrical fluorene derivatives based on structural types of acceptor-pi-acceptor, acceptor-pi-donor, and donor-pi-donor were characterized by TGA, UV-vis absorption, fluorescence emission, lifetime, anisotropy, and two-photon absorption (2PA) cross section. They were found to possess high thermal stability, high photostability, high fluorescence quantum yields, and generally large two-photon absorption cross sections, making them quite suitable for new probes in single-photon absorption and two-photon absorption fluorescence microscopy imaging. Novel …

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Reactions Of Rhenium And Manganese Carbonyl Complexes With 1,8-Bis(Diphenylphosphino)Naphthalene: Ligand Chelation, C–H And C–P Bond-Cleavage Reactions, Shariff E. Kabir, Faruque Ahmed, Shishir Ghosh, Mohammad R. Hassan, Muhammad S. Islam, Ayesha Sharmin, Derek A. Tocher, Daniel T. Haworth, Sergey V. Lindeman, Tasneem Siddiquee, Dennis W. Bennett, Kenneth I. Hardcastle Aug 2008

Reactions Of Rhenium And Manganese Carbonyl Complexes With 1,8-Bis(Diphenylphosphino)Naphthalene: Ligand Chelation, C–H And C–P Bond-Cleavage Reactions, Shariff E. Kabir, Faruque Ahmed, Shishir Ghosh, Mohammad R. Hassan, Muhammad S. Islam, Ayesha Sharmin, Derek A. Tocher, Daniel T. Haworth, Sergey V. Lindeman, Tasneem Siddiquee, Dennis W. Bennett, Kenneth I. Hardcastle

Chemistry Faculty Research and Publications

Reaction of [Re2(CO)8(MeCN)2] with 1,8-bis(diphenylphosphino)naphthalene (dppn) afforded three mono-rhenium complexes fac-[Re(CO)3(κ1:η1-PPh2C10H6)(PPh2H)] (1), fac-[Re(CO)3{κ1:κ1:η1-(O)PPh2C10H6(O)PPh(C6H4)}] (2) and fac-[ReCl(CO)3(κ2-PPh2C10H6PPh2)] (3). Compounds 1–3 are formed by Re–Re bond cleavage and P–C and C–H bond activation of the dppn ligand. Each of these three …

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Preparation Of 1,5-Diketones By Addition Of Cyclohexanone To Chalcones Under Solvent-Free Phase Transfer Catalyst Condition, Mustafa Ceylan, Hayretti̇n Gezegen Jan 2008

Preparation Of 1,5-Diketones By Addition Of Cyclohexanone To Chalcones Under Solvent-Free Phase Transfer Catalyst Condition, Mustafa Ceylan, Hayretti̇n Gezegen

Turkish Journal of Chemistry

Eight different chalcone-1,5-diketone derivatives (5a-h) were prepared by the reaction of chalcone derivatives (3a-h) with cyclohexanone under the solvent-free phase transfer catalyst condition with modarate to high yields. The mechanistic pathway of the reaction can be explained by the Michael-type addition of cyclohexanone to chalcone derivatives (3a-h).

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The Synthesis And Anticonvulsant Activity Of 1-Substituted-7-Methoxy-1,2,4-Triazolo [4,~3-A]Quinoline, Li-Ping Guan, Xian-Yu Sun, Guan-Rong Tian, Kyu-Yun Chai, Zhe-Shan Quan Jan 2008

The Synthesis And Anticonvulsant Activity Of 1-Substituted-7-Methoxy-1,2,4-Triazolo [4,~3-A]Quinoline, Li-Ping Guan, Xian-Yu Sun, Guan-Rong Tian, Kyu-Yun Chai, Zhe-Shan Quan

Turkish Journal of Chemistry

A new series of 1-substituted-7-methoxy-5-phenyl-1,2,4-triazolo [4,3-a]quinolines were synthesized using ethyl-3-oxo-3-phenylpropanoate and 4-methoxybenzenamine as the starting material. Their anticonvulsant activity was evaluated by the maximal electroshock (MES) test and 7-methoxy-5-phenyl-1,2,4-triazolo[4,3-a]quinoline (4a) was identified as the most potent compound, with an ED_{50} value of 9.2 mg kg^{-1}, which is comparable to the reference drug phenytoin (ED_{50} = 9.9 mg kg^{-1}). To explore the possible mechanism of its anticonvulsant activity, compound 4a was tested with the rotarod neurotoxicity test, pentylenetetrazole (sc-PTZ) test, and isoniazid test. Compound 4a had a higher protective index (PI = TD_{50}/ED_{50}) value (16.6) than phenytoin (PI = 7.0), and …

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Synthesis And Characterization Of New Tridentate Iminooxime Ligands And Their Co(Iii) Complexes, Hasene Mutlu, Gazi̇ İrez Jan 2008

Synthesis And Characterization Of New Tridentate Iminooxime Ligands And Their Co(Iii) Complexes, Hasene Mutlu, Gazi̇ İrez

Turkish Journal of Chemistry

In this study, (hydroxyimino)(2-phenyl(1,2,3,4-tetrahydroquinazolin- 2-yl))methane (H_2L^1) and (hydroxyimino)(2-(2-thienyl)(1,2,3,4- tetrahydroquinazolin-2-yl))methane (H_2L^2) were synthesized by the condensation of 2-(hydroxyimino)-1-phenylethan-1-one (INAP) and 2-(hydroxyimino)-1-(2-thienyl)ethan-1-one (INAT) with 2-aminobenzylamine (2-ABA). Complexes of these ligands with Co^{3+} were prepared with a metal:ligand ratio of 1:2. The ligands and their complexes were elucidated on the basis of elemental analyses, AAS, FT-IR, ^1H- and ^{13}C-NMR spectra, mass spectra, magnetic susceptibility measurements, and molar conductivity.

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Synthesis And Characterizations Of Some New 4h-1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Şule Ceylan, Deni̇z Şahi̇n Jan 2008

Synthesis And Characterizations Of Some New 4h-1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Şule Ceylan, Deni̇z Şahi̇n

Turkish Journal of Chemistry

3-[(5-Amino-1,3,4-thiadiazol-2-yl)methyl]-4-ethoxycarbonylamino-5-alkyl-4H-1,2,4-triazoles (2a,b) were obtained from the reaction of 3-cyanomethyl-5-alkyl-4-ethoxycarbonylamino-4H-1,2,4-triazoles (1a,b) with thiosemicarbazide in the presence of trifluoroacetic acid. The treatment of the obtained compounds (2a,b) with acetic anhydride for 1 h afforded 3-[(5-acetylamino-1,3,4-thiadiazol-2-yl)methyl]-4-ethoxycarbonylamino-5-alkyl-4H-1,2,4-triazoles (3a,b). The synthesis of 4-ethoxycarbonylamino-3-[(2,3-dihydro-1,3-benzoxazol-2-yl)methyl]-5-(4-methylbenzyl)-4H-1,2,4-triazole (4) was performed by the treatment of 3-[(5-acetylamino-1,3,4-thiadiazol-2-yl)methyl]-4-ethoxycarbonylamino-5-(4-methylbenzyl)-4H-1,2,4-triazole (3a) with o-aminophenol under nitrogen atmosphere for 50 h. The reaction of compounds 1a,b with salicylaldehyde in the presence of sodium ethoxide yielded 2-{4-[(ethoxycarbonyl)amino]-5-alkyl-4H-1,2,4-triazol-3-yl}-3-(2-hydroxyphenyl)-acrylonitriles (5a,b). The acetylations of compounds 5a,b with acetic anhydride for 5 h resulted in the formation of 2-{4-[acetyl(ethoxycarbonyl)amino]-5-alkyl-4H-1,2,4-triazol-3-yl}-3-[2-(acetyloxy)phenyl]-acrylic acids (6a,b). On the other hand, the treatment of compounds 5a,b with …

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One Step Synthesis Of Some 2,5,6-Trisubstituted-1,3-Dioxin-4-Ones, Ahmet Şener, İshak Bi̇ldi̇ri̇ci̇, Hasan Genç, Nuretti̇n Mengeş, Siddik Eski̇noba Jan 2008

One Step Synthesis Of Some 2,5,6-Trisubstituted-1,3-Dioxin-4-Ones, Ahmet Şener, İshak Bi̇ldi̇ri̇ci̇, Hasan Genç, Nuretti̇n Mengeş, Siddik Eski̇noba

Turkish Journal of Chemistry

A number of novel 2,5,6-trisubstituted-1,3-dioxin-4-one derivatives were synthesized via one step reactions between dibenzoylmethane or benzoylacetone and oxalyl chloride in refluxing solvents containing various aldehydes.

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Synthesis And Characterization Of Novel Azole Heterocycles Based On 2,5-Disubstituted Thiadiazole, Nadia A. Salih Jan 2008

Synthesis And Characterization Of Novel Azole Heterocycles Based On 2,5-Disubstituted Thiadiazole, Nadia A. Salih

Turkish Journal of Chemistry

Starting from 2-amino-5-mercapto-1,3,4-thiadiazole (1), a variety of new 1,2,4-triazino[5,4-b][1,3,4] thiadiazole (3), pyrazole (4), [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazole (5), phthalazine-3,6-dione (6), azo derivatives (9), pyrimidine -2,4,6-trione (11), Schiff base (12) and pyrrolidine (13) derivatives have been synthesized. All proposed structures were supported by FT-IR, ^1H-NMR, ^{13}C-NMR elemental analysis, and MS spectroscopic data.

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Microwave-Assisted Synthesis Of 1,4´-Diazaflavone And N-Alkyl Derivative Pigments With Anti-Microbial Activity, Nuran Yayli, Osman Üçüncü, Nuretti̇n Yayli, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ Jan 2008

Microwave-Assisted Synthesis Of 1,4´-Diazaflavone And N-Alkyl Derivative Pigments With Anti-Microbial Activity, Nuran Yayli, Osman Üçüncü, Nuretti̇n Yayli, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ

Turkish Journal of Chemistry

1,4'-Diazaflavone pigment (2) was synthesized by a simple environmentally friendly microwave-assisted one-pot method for the cyclization of 2'-amino (E)-4''-aza-chalcone (1) under solventless conditions using K-10 clay. In addition, 10 new N-alkyl (C_{5-12, 14-15}) substituted 1,4' -diazaflavonium bromide pigments (3-12) were prepared from compound 2 or directly from compound 1, with corresponding alkyl halides in acetonitrile under reflux. The anti-microbial activity of compounds 1-12 was tested. The N-alkyl substituted 1,4' -diazaflavonium bromides (3-12) showed good antimicrobial activity against the gram-positive bacteria tested with minimal bactericidal concentration (MBC) values for the reference antibiotic kanamycin. The optimum length of the alkyl chain for …

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Preconcentration Of Trace Elements On Amberlite Xad-4 Resin Functionalised With 1,2-Bis (O-Aminophenylthio) Ethane And Their Determination By Faas In Environmental Samples, Ömer Dalman, Volkan Numan Bulut, İsmai̇l Deği̇rmenci̇oğlu, Mehmet Tüfekçi̇ Jan 2007

Preconcentration Of Trace Elements On Amberlite Xad-4 Resin Functionalised With 1,2-Bis (O-Aminophenylthio) Ethane And Their Determination By Faas In Environmental Samples, Ömer Dalman, Volkan Numan Bulut, İsmai̇l Deği̇rmenci̇oğlu, Mehmet Tüfekçi̇

Turkish Journal of Chemistry

The use of chemically modified XAD-4-1,2-bis (o-aminophenylthio) ethane chelating resin for preconcentrating Cr^{6+}, Mn^{2+}, Fe^{3+}, Co^{2+}, Cu^{2+}, Cd^{2+}, Zn^{2+}, Pb^{2+}, and Ni^{2+} was studied using flame atomic absorption spectrometry (FAAS) for metal monitoring in environmental samples. Cd^{2+}, Zn^{2+}, Pb^{2+}, and Ni^{2+} ions were quantitatively recovered at the rate of 96.0%, 101.0%, 101.0%, and 95.0%, respectively (RSD < 5%), from the studied solutions. The procedure is based on the retention of analytes on a short column of 1,2-bis (o-aminophenylthio) ethane-XAD-4 chelating resin from a buffered sample solution and subsequent elution with 1 M HNO_3. Various parameters, such as pH, eluent type, and concentration, flow rate of sample solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH for the sorption of the above-mentioned metal ions was about 6. The adsorption and batch capacity of adsorbent and loading half time (t_{1/2}) for Ni^{2+}, Zn^{2+}, Cd^{2+}, and Pb^{2+} were established. The limit of detection was 3.0 \mu g L^{-1} for Pb^{2+} and Ni^{2+}, 0.6 \mu g L^{-1} for Cd^{2+}, and 0.3 \mu g L^{-1} for Zn^{2+}. The validation of the procedure was carried out by analysis of certified reference materials and standard addition. The proposed enrichment method was applied to environmental samples from Trabzon.

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Synthesis Of 2-Acylamino, 2-Aroylamino And Ethoxycarbonyl Imino-1,3,4-Thiadiazoles As Antitumor Agents, Kemal Sancak, Yasemi̇n Ünver, Mustafa Er Jan 2007

Synthesis Of 2-Acylamino, 2-Aroylamino And Ethoxycarbonyl Imino-1,3,4-Thiadiazoles As Antitumor Agents, Kemal Sancak, Yasemi̇n Ünver, Mustafa Er

Turkish Journal of Chemistry

2-Amino-1,3,4-thiadiazoles compounds (2a-e) were obtained from the reaction of thiosemi carbazide with 2-cyanomethoxyphenoxyacetonitriles (1). Mono acylamino, mono aroylamino and diethoxycarbonyl imino-1,3,4-thiadiazole compounds (3a-e, 4a-e, 5a-c) were synthesized via the reaction of 2-amino-1,3,4-thiadiazole compounds (2a-e) with acetyl chloride or acetic anhydride, benzoyl chloride or benzoic anhydride and ethyl chloroformate, respectively. The in vitro antitumor activities of some selected compounds were screened and compounds 2a, 2b, 2c, 3a, 3b, 3c, 5a, 5b and 5c were found to be active.

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Synthesis Of Some New 1-Acylthiosemicarbazides And 1,2,4-Triazol-5-Thiones, And Their Analgesic And Anti-Inflammatory Activities, Yasemi̇n Dündar, Bi̇lge Çakir, Esra Küpeli̇, M. Fethi̇ Şahi̇n, Ni̇ngur Noyanalpan Jan 2007

Synthesis Of Some New 1-Acylthiosemicarbazides And 1,2,4-Triazol-5-Thiones, And Their Analgesic And Anti-Inflammatory Activities, Yasemi̇n Dündar, Bi̇lge Çakir, Esra Küpeli̇, M. Fethi̇ Şahi̇n, Ni̇ngur Noyanalpan

Turkish Journal of Chemistry

We synthesized new 1-[3-(2-oxobenzothiazolin-3-yl)propanoyl]-4- substituted-thiosemicarbazides and their corresponding cyclized 3-[2-(2-oxobenzothiazoline-3-yl)ethyl]-4-substituted-1,2,4-triazol-5-thione ana-logs in which position 4 of the triazole ring was substituted by cyclohexyl, methyl, allyl, phenyl, p-methylphenyl, p-methoxyphenyl, p-chlorophenyl, p-nitrophenyl, benzyl, and phenylethyl to screen their analgesic and anti-inflammatory activities as well as gastric ulceration potential in test animals. None of the compounds, except 5a, 5e, and 5h, caused gastric lesions or bleeding. Compound 5g was found to have higher analgesic and anti-inflammatory activity among the synthesized compounds.

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Synthesis Of Some Novel 3,5-Diaryl-1,2,4-Triazole Derivatives And Investigation Of Their Antimicrobial Activities, Mevlut Serdar, Nurhan Gümrükçüoğlu, Şengül Alpay Karaoğlu, Nesli̇han Demi̇rbaş Jan 2007

Synthesis Of Some Novel 3,5-Diaryl-1,2,4-Triazole Derivatives And Investigation Of Their Antimicrobial Activities, Mevlut Serdar, Nurhan Gümrükçüoğlu, Şengül Alpay Karaoğlu, Nesli̇han Demi̇rbaş

Turkish Journal of Chemistry

A series of acylhydrazones (2a-d) was synthesized from the reactions of iminoester hydrochlorides (1a-e) with acyl hydrazines. 2,5-Dialkyl 1,3,4-oxadiazoles (3a-d) were obtained in the same reaction media. The treatment of acylhydrazones with hydrazine hydrate afforded 4-amino-3,5-dialkyl-1,2,4-triazoles (4a-c). The acetylation of 4-amino-3-(4-hydroxyphenyl)-5-phenyl-4H-1,2,4-triazole (4a) produced 4-amino-5-(4-acetoxyphenyl)-3-phenyl-4H-1,2,4-triazole (9), while the acetylation of 4-amino-3-(4-tolyl)-5-phenyl-4H-1,2,4-triazole (4b) gave 4-acetylamino-3-phenyl-5-(4-tolyl)-4H-1,2,4-triazole (10). The treatment of compound 4b with various aromatic aldehydes or acetophenone and 4-nitroacetophenone resulted in the formation of 4-arylidenamino-3,5-dialkyl-4H-1,2,4-triazoles (5a-e and 7a,b). Sodium borohydride reduction of 4-arylidenamino derivatives of 1,2,4-triazoles afforded 4-alkylamino-3,5-dialkyl-4H-1,2,4-triazoles (6a-e and 8a,b). All newly synthesized compounds were screened for their antimicrobial and antifungal …

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Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nurhan Gümrükçüoğlu, Mevlut Serdar, Eli̇f Çeli̇k, Ali̇ Sevi̇m, Nesli̇han Demi̇rbaş Jan 2007

Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nurhan Gümrükçüoğlu, Mevlut Serdar, Eli̇f Çeli̇k, Ali̇ Sevi̇m, Nesli̇han Demi̇rbaş

Turkish Journal of Chemistry

A series of acylhydrazones (2a-f) were synthesized by the condensation of iminoester hydrochlorides (1a-f) with acyl hydrazines. 2,5-Dialkyl 1,3,4-oxadiazoles (3a,c,e) were obtained in the same reaction media. The treatment of acylhydrazones with hydrazine hydrate afforded 4-amino-3,5-dialkyl-1,2,4-triazoles (4a-c). The acetylation of 4-amino-3,5-dialkyl-1,2,4-triazoles produced N-[3,5-dialkyl-4H-1,2,4-triazol-4-yl] acetamides (5-7). The treatment of compounds 4a and 4c with various aromatic aldehydes resulted in the formation of 4-arylidenamino-3,5-dialkyl-1,2,4-triazoles (8a,d, e, and 10a-e). Sodium borohydride reduction of 4-arylidenamino derivatives afforded 4-alkylamino-3,5-dialkyl-1,2,4-triazoles (9a,d, e, and 11a-e). Compounds 4b, 4c, 7, 8d, and 11c showed good antifungal activity only against yeast-like fungi, while compounds 3e, 6, 8e, and 9e …

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Kinetics And Mechanism Of Oxidation Of 1,3--Butylene Glycol By Dihydroxyditellutoargentate(Iii) In Alkaline Medium, Jin-Huan Shan, Shu-Ying Huo, Shi-Gang Shen, Han-Wen Sun Jan 2006

Kinetics And Mechanism Of Oxidation Of 1,3--Butylene Glycol By Dihydroxyditellutoargentate(Iii) In Alkaline Medium, Jin-Huan Shan, Shu-Ying Huo, Shi-Gang Shen, Han-Wen Sun

Turkish Journal of Chemistry

The kinetics of oxidation of 1,3--butlene glycol (\beta - BG) by dihydroxyditelluto- argentate(III) were studied spectrophotometrically between 298.2 and 313.2 K in alkaline medium. The reaction rate showed pseudo-first order dependence in oxidant and fractional order in \ss-BG. The pseudo-first order rate constant k_{obs} increased with an increase in the concentration of OH^- and a decrease in the concentration of TeO_4^{2-} . There was a negative salt effect and no free radicals were detected. Thus, the dihydroxymonotelluratoargentate(III) species is assumed to be the active species. The activation parameters along with the rate constants of the rate-determining step were calculated.

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Manganese(Iii) Acetate Mediated Free Radical Cyclization Of 1,3-Dicarbonyl Compounds With Sterically Hindered Olefins, Mehmet Yilmaz, Emre Bi̇çer, A. Tarik Pekel Jan 2005

Manganese(Iii) Acetate Mediated Free Radical Cyclization Of 1,3-Dicarbonyl Compounds With Sterically Hindered Olefins, Mehmet Yilmaz, Emre Bi̇çer, A. Tarik Pekel

Turkish Journal of Chemistry

The manganese(III) acetate mediated radical cyclization of dimedone 1a, 2,4-pentanedione 1b, ethyl acetoacetate 1c, 1,3-cyclohexanedione 1d and 5-phenyl-1,3-cyclohexanedione 1e with 1,1-diphenyl-1-butene 2a afforded 4,5-dihydrofurans (3c, 3e) and tetrahydrobenzofurans (3a, 3g, 3h) in good yields (55% - 77%). Additionally, the reactions of trifluoromethyl-group containing 1,3-dicarbonyls, 4,4,4-trifluoro-1-phenylbutane-1,3-dione 1f and 4,4,4-trifluoro-1-thien-2ylbutane-1,3-dione 1g with 2a 3-trifluoroacetyl-4,5-dihydrofurans gave in 74% and 78% yields, respectively. Treatment of 1a, 1b and 1c with 1,2-diphenyl-1-pentene 2a resulted in the formation of tetrahydrobenzofuran 3b and 4,5-dihydrofurans 3d and 3f in lower yields.

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Synthesis Of Some New Isoxazolidines By 1,3-Dipolar Cycloaddition Reaction Of Nitrones And Olefins, Akbar Mobinikhaledi, Naser Forughifar, Zahra Kalate Jan 2005

Synthesis Of Some New Isoxazolidines By 1,3-Dipolar Cycloaddition Reaction Of Nitrones And Olefins, Akbar Mobinikhaledi, Naser Forughifar, Zahra Kalate

Turkish Journal of Chemistry

A series of new isoxazolidines 5a-j were synthesized by 1,3-dipolar cycloaddition reaction of different nitrones with substituted olefins under reflux condition. The yields of products following recrystallization from absolute ethanol were of the order of 40%-66%. IR, NMR and mass spectroscopies were used for identification of these compounds.

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Synthesis And Characterization Of New Triheterocyclic Compounds Consisting Of 1,2,4-Triazol-3-One, 1,3,4-Thiadiazole And 1,3,4-Oxadiazole Rings, Nesli̇han Demi̇rbaş Jan 2005

Synthesis And Characterization Of New Triheterocyclic Compounds Consisting Of 1,2,4-Triazol-3-One, 1,3,4-Thiadiazole And 1,3,4-Oxadiazole Rings, Nesli̇han Demi̇rbaş

Turkish Journal of Chemistry

A series of acetic acid derivatives (2a-c) was synthesized by the condensation of compounds 1a-c with chloroacetic acid. The treatment of carboxylic acid derivatives with thiosemicarbazide in phosphorus oxychloride and subsequent diazotation of the products (3a-c) afforded 5-alkyl-2-[(5-chloro-1,3,4-thiadiazol-2-yl)methyl]- 2,4-dihydro-3H-1,2,4-triazol-3-one derivatives (4a-c). The treatment of compounds 4a-c with thiourea produced 5-alkyl-2-[(5-mercapto-1,3,4- thiadiazol-2-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one derivatives (5a-c). Subsequently, compounds 5a-c were converted to acid hydrazides by treatment with hydrazine hydrate after esterification (7a-e). Moreover, the reaction of compounds 7a-c with carbon disulfite in the presence of KOH afforded 5-alkyl-2-[(5-\{[(5- mercapto-1,3,4-oxadiazol-2-yl)methyl]thio\}-1,3,4-thiadiazol-2-yl)methyl]- 2,4-dihydro-3H-1,2,4-triazol-3-ones (8a-c).

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Studies On The Electrochemical Behavior Of Copper Paratolysulfate And Its Complexes, Ji-Guo Song, Pei-Kang Shen Aug 2004

Studies On The Electrochemical Behavior Of Copper Paratolysulfate And Its Complexes, Ji-Guo Song, Pei-Kang Shen

Journal of Electrochemistry

Copper (II) paratolysulfate has been synthesized and characterized by thermo-gravimetric (TG) measurements and differential scanning calorimetric (DSC) analysis. This salt can easily lose all crystal water and the dehydrated salt does not deliquesce in the air. It is found for the first time that the complex of Cu(p-OTs)2/ethanolamine(1∶1) can catalyze the oxidation of 1,1′-bi-2-naphthol in DMSO and DMF, while the process is difficult to perform in H2O and CH3OH. The electrochemical behaviors of both Cu(p-OTs)2 and its complexes with ethanolamine have been studied on platinum electrode in DMSO, DMF, CH3OH and …

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Synthesis And Reactivity Of Tetrahydroimidazo [1,5-B][1,2,4]Oxadiazol- 2(1h)-Thiones, Necdet Coşkun, Fatma Ti̇rli̇ Tat Jan 2004

Synthesis And Reactivity Of Tetrahydroimidazo [1,5-B][1,2,4]Oxadiazol- 2(1h)-Thiones, Necdet Coşkun, Fatma Ti̇rli̇ Tat

Turkish Journal of Chemistry

1,3-Dipolar cycloaddition of imidazoline 3-oxides 1 with methylisothiocyanate proceeds regio- and diastereoselectively to give tetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2(1H)-thiones 3 in high yields. The cis configuration of the adducts was proved by our double cis elimination test as well as by NOESY experiments. Adducts 3a-c undergo ring opening at reflux in acetonitrile to give imidazoles while 3d-e undergo retro dipolar cycloaddition to give the starting nitrones 1d-e. The imidazooxadiazol-2-thiones 3a-e were treated with concentrated HCl in ethanol at 50 °C to give the corresponding 4H-[1,2,4]oxadiazole-5-thione only in cases in which the substituent at C-6 is an aryl.

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Chalcogeno Ureas Derived From Bis(1,3-Diazepan-2-Ylidene), Yetki̇n Gök, Engi̇n Çeti̇nkaya Jan 2004

Chalcogeno Ureas Derived From Bis(1,3-Diazepan-2-Ylidene), Yetki̇n Gök, Engi̇n Çeti̇nkaya

Turkish Journal of Chemistry

A series of new electron rich olefins (=\overset{ } CNR(CH_2)_4\overset{ }NR)_2, 3, (a; R = CH_2C_6H_5, b; R = CH_2C_6H_4-OMe-p, c; R = CH_2C_6H_4-NMe_2-p) was generated via the condensation of RNH(CH_2)_4NHR with Me_2NCH (OMe)_2. The C=C bond cleavage reactions of 3 with S_8 and Se provide a simple and straightforward method for the synthesis of 1,3-diazepan-2-chalcogenones 4 and 5, respectively.

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Synthesis And Antinociceptive Activity Of 2-[(2-Oxobenzothiazolin-3-Yl)Methyl]- 5-Aminoalkyl/Aryl-1,3,4-Thiadiazole, Ti̇jen Önkol, Bi̇lge Çakir, M. Fethi̇ Şahi̇n, Engi̇n Yildirim, Kevser Erol Jan 2004

Synthesis And Antinociceptive Activity Of 2-[(2-Oxobenzothiazolin-3-Yl)Methyl]- 5-Aminoalkyl/Aryl-1,3,4-Thiadiazole, Ti̇jen Önkol, Bi̇lge Çakir, M. Fethi̇ Şahi̇n, Engi̇n Yildirim, Kevser Erol

Turkish Journal of Chemistry

Ten 2-[(2-oxobenzothiazolin-3-yl)methyl]-5-aminoalkyl/aryl-1,3,4-thiadiazole derivatives were synthesized. The chemical structures of these compounds were elucidated by their FT-IR and ^1H-NMR spectral data, as well as their elemental analyses. The compounds were tested for antinociceptive activity. Among these compounds, 2-[(2-oxobenzothiazolin-3-yl)methyl]-5-aminomethyl-1,3,4-thiadiazole (5a) was found to be significantly more active than the others and the standards in all the tests.

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Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu Jan 2004

Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu

Turkish Journal of Chemistry

A series of 4-(1-naphthylidenamino)-1,2,4-triazol-5-one derivatives (3a-e) were synthesized by condensation of corresponding 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with 1-naphthaldehyde. Acetylation and alkylation of these compounds gave 4a-e and 5a-e, respectively. Sodium borohydride reduction of 1-naphthylidenamino derivatives afforded naphthylmethylamino derivatives, which were subsequently acetylated. Depending on the duration of the acetylation, mono or bis acetamide derivatives were obtained. The in vitro antitumor activities of some selected compounds were screened and compounds 3e, 5c, 6e and 9c} were found to be active.

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The Kinetic Study Of The Chemical Oscillating System Of 1,3-Propanediol/Acetone As The Organic Substrate, Shi-Gang Shen, Caiqin Yang, Han-Wen Sun, Jin-Huan Shan, Ying Liu Jan 2003

The Kinetic Study Of The Chemical Oscillating System Of 1,3-Propanediol/Acetone As The Organic Substrate, Shi-Gang Shen, Caiqin Yang, Han-Wen Sun, Jin-Huan Shan, Ying Liu

Turkish Journal of Chemistry

This work was primarily an experimental investigation of the bromate oscillator using 1,3-propanediol and acetone as the mixed organic substrates. The empirical equation of the induction period and oscillating period with the concentrations of the reactants and temperature were obtained. The oscillating characteristic and possible oscillation mechanism were studied.

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Synthesis And Characterization Of Some 3-Alkyl-4-Amino-5-Cyanomethyl-4h-1,2,4-Triazoles, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Kemal Sancak Jan 2002

Synthesis And Characterization Of Some 3-Alkyl-4-Amino-5-Cyanomethyl-4h-1,2,4-Triazoles, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Kemal Sancak

Turkish Journal of Chemistry

The preparation and characterization of some 3-alkyl-4-amino-5-cyanomethyl-4H-1,2,4-triazoles with active methylene groups are described and their structural properties using NMR and IR spectra and elemental analyses are given.

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