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Synthesis Of New Oxindole Derivatives Containing Benzothiazole And Thiazolidinone Moieties Using Nano Silica-Bonded 5-N-Propyl-Octahydro-Pyrimido[1,2-A]Azepinium Chloride (Nsb-Dbu) As Catalyst, Robabeh Baharfar, Narges Shariati

Turkish Journal of Chemistry

A facile one-pot synthesis of novel oxindole derivatives bearing benzothiazolylmethyl-2-thioxothiazolidin-4-one was accomplished via one-pot reaction of 5-oxoindolinylidene rhodanine-3-acetic acid derivatives, 2-aminothiophenol, and triphenyl phosphite in the presence of tetrabutylammonium bromide (TBAB) and nano silica-bonded 5-n-propyl-octahydro-pyrimido[1,2-a]azepinium chloride (NSB-DBU) as heterogeneous reusable nanocatalyst. The target compounds were obtained in excellent yields (85%--92%) and short reaction times under fairly mild reaction conditions.

Regiospecific One-Pot, Combinatorial Synthesis Of New Substituted Pyrimido[4,5-C]Pyridazines As Potential Monoamine Oxidase Inhibitors, Mehdi Rimaz, Paria Pourhossein, Behzad Khalili

Turkish Journal of Chemistry

New 3-aryl-6-methylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-diones and 3-aryl-6-ethyl-7-thioxo-7,8-dihydropyrimido[4,5-c]pyridazin-5(6H)-ones were efficiently synthesized via a regiospecific one-pot reaction of N-methylbarbituric acid and N-ethyl-2-thiobarbituric acid with various arylglyoxal monohydrates in the presence of hydrazine dihydrochloride in ethanol at 50 °C. The target compounds were obtained in high yields and were regioisomerically pure after recrystallization. These new heterocycles may act as potential MAO_{B} inhibitors.

Synthesis And Biological Evaluation Of New Pyridines Containing Imidazole Moiety As Antimicrobial And Anticancer Agents, Ikhlass Abbas, Sobhi Gomha, Mahmoud Elaasser, Mohammed Bauomi

Turkish Journal of Chemistry

The synthesis of a novel series of pyridine and bipyridine derivatives is described via one-pot multicomponent reaction of 5-acetylimidazole, malonitrile (or ethylcyanoacetate or diethylmalonate), substituted benzaldehyde (or terephthaldehyde), and ammonium acetate in good yields. The structures of all the new compounds were elucidated on the basis of elemental analysis and spectral data. The antimicrobial activities of the synthesized compounds were screened and the results showed that most of such compounds exhibit considerable activities. Furthermore, some of the newly synthesized compounds were screened for their anticancer activity against human breast cell line (MCF-7) and liver carcinoma cell line (HEPG2) in comparison …

Nmr T₁ Studies Of Colloidal Unimolecular Polymer (Cup) Surface Water, Yousef Abobaker Dawib

Doctoral Dissertations

"This dissertation is subdivided into three topics: Experimental study of colloidal unimolecular polymer (CUP) hydration; probing of polymer chain dynamics by ¹³C solid state NMR technique; and the anticorrosive effect of 5-mercapto-1, 3, 4-thiadiazole-2(3H)-thione (MTT) derivatives.

The states of water in colloidal unimolecular polymer system were investigated by low field proton NMR. Bound and free water fractions were determined using spin-lattice relaxation measurements. A model equation was used to analyze the inversion recovery data.

The proton cross polarization and the pulse sequence for total spinning sideband suppression CP-TOSS NMR method were developed to determine the chain mobility of polymers …

Effects Of N-Acetylcysteine Amide In Preventing/Treating Cataracts, Sri Krishna Yasaswi Maddirala

Doctoral Dissertations

"Cataract, the opacification of an eye lens, is a common pathological abnormality of the lens accounting for approximately 50% of all blindness. The only effective treatment currently available for a cataract is the surgical removal of the affected lens and replacement with an artificial lens for the restoration of vision. Although, cataract surgery is considered to be a very successful procedure in terms of visual outcome, the cost of surgery, need for trained personnel and surgeons, and postsurgical complications, limit the worldwide availability and accessibility of this procedure. Hence, alternative preventive and treatment procedures are worthy of investigation. The lens …

Controlled Deposition Of Tin Oxide And Silver Nanoparticles Using Microcontact Printing, Joo C. Chan, Nicole Hannah-Moore, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

This report describes extensive studies of deposition processes involving tin oxide (SnO_x) nanoparticles on smooth glass surfaces. We demonstrate the use of smooth films of these nanoparticles as a platform for spatially-selective electroless deposition of silver by soft lithographic stamping. The edge and height roughness of the depositing metallic films are 100 nm and 20 nm, respectively, controlled by the intrinsic size of the nanoparticles. Mixtures of alcohols as capping agents provide further control over the size and shape of nanoparticles clusters. The distribution of cluster heights obtained by atomic force microscopy (AFM) is modeled through a modified …

Synthesis And Molecular Modeling Studies Of Naproxen-Based Acyl Hydrazone Derivatives, Tuğba Taşkin Tok, Özgün Özaşik, Deni̇z Sarigöl, Ayşe Uzgören Baran

Turkish Journal of Chemistry

A series of N-acylhydrazone derivatives (2a--2p) containing 6-methoxy-naphthalene and acylhydrazone moieties were synthesized in good yield using microwave irradiation and developed as potential COX-2 inhibitors. Furthermore, the interactions between COX-2 and the compounds were examined in detail by molecular modeling studies such as structure--activity relationship and molecular docking performed using Gaussian 09 and Discovery Studio 3.5. As a result, it was found that N-acylhydrazone compounds displayed a different mechanism than SC-558 as COX-2 inhibitor by binding to different active sites of the protein, COX-2. Compound 2c would be a good COX-2 inhibitor candidate for preclinical studies.

Kinetics And Performance Studies Of A Switchable Solvent Tmg (1,1,3,3-Tetramethylguanidine)/1-Propanol/Carbon Dioxide System, Özge Yüksel, Mustafa Çağdaş Öztürk, Ayça Şeker, Erdoğan Alper

Turkish Journal of Chemistry

The rate constants and the activation energies of the reaction between carbon dioxide and 1,1,3,3-tetramethylguanidine (TMG) in 1-propanol solution were measured by a stopped-flow technique at a temperature range of 288--308 K and at a TMG concentration range of 2.5--10.0 wt %. Based on the pseudo-first-order reaction for CO_2, the reaction was modeled by a termolecular reaction mechanism, which resulted in a rate constant of 199.30 m^3 kmol^{-1} s^{-1} at 298 K. The activation energies were 5.19 kJ/mol and 5.26 kJ/mol at 2.5 and 5.0 wt % TMG, respectively. In addition, carbon dioxide absorption capacity was investigated using a gas--liquid …

Synthesis And Characterization Of Substituted Benzimidazole Co(Ii), Fe(Ii), And Zn(Ii) Complexes And Structural Characterization Of Dichlorobis{1-[2-(1-Piperidinyl)Ethyl]-1h-Benzimidazole-_Kn^3} Zinc(Ii), Hasan Küçükbay, Ülkü Yilmaz, Mehmet Akkurt, Orhan Büyükgüngör

Turkish Journal of Chemistry

The Co(II), Fe(II), and Zn(II) complexes of 1-(3-phenyl)propylbenzimidazole (PPBI), 5-nitro-1-(3-phenyl) propylbenzimidazole (PPNBI), 1-[2-(4-morpholinyl)ethyl]benzimidazole (MEBI), 1-[2-(1-piperidinyl)ethyl]benzimidazole (PEBI), and 5-nitro-1-[2-(1-piperidinyl)ethyl]benzimidazole (PENBI) were synthesized and characterized by ^1H NMR, ^{13}C NMR, and elemental analyses. The magnitudes of the magnetic moments for paramagnetic complexes were between 4.07 and 5.11 B.M. Moreover, the crystal structure of dichlorobis{1-[2-(1-piperidinyl)ethyl]-1H-benzimidazole-_KN^3} zinc(II) was determined by single crystal X-ray diffraction.

Synthesis Of Tetrahydropyrimidinium Salts And Their In Situ Catalytic Activities Towards The Buchwald--Hartwig Amination Reaction Under Microwave Irradiation, Liangru Yang, Huanyu Bian, Wenpeng Mai, Pu Mao, Yongmei Xiao, Dong Wei, Lingbo Qu

Turkish Journal of Chemistry

A series of asymmetrical substituted tetrahydropyrimidinium salts and different kinds of bridged bis-tetrahydropyrimidinium salts were prepared through the quaterization of tetrahydropyrimidine or the dehydrogenation of hexahydropyrimidine. They were characterized and used as NHC precursors in the palladium catalyzed Buchwald--Hartwig amination reaction. The in situ formed catalytic system Pd(OAc)_2/tetrahydropyrimidinium and ^tBuOK catalyzed the amination of heteroaryl halides and heterocyclic amines effectively, producing the heterocyclic amine functionalized heteroaryl derivatives in high yields.

Purification And Characterization Of Nadph-Cytochrome P450 Reductase From Lake Van Fish Liver Microsomes And Investigation Of Some Chemical And Metals' Effects On The Enzyme Activity, Müslüm Kuzu, Mehmet Çi̇ftci̇

Turkish Journal of Chemistry

NADPH-cytochrome P450 reductase was purified from Lake Van fish liver microsomes by primary and secondary DEAE-cellulose column chromatograph with 20.46 \mu M/min/mg enzyme specific activities, 54.4% purification yield, and purification of 38-fold. The purity of the enzyme was established, and its monomer molecular weight was determined by SDS-polyacrylamide gel electrophoresis. SDS-PAGE results showed a single band and the molecular weight of NADPH-cytochrome P450 reductase was 70 kDa. In addition, optimum ionic strength, optimum pH, optimum temperature, and stable pH values were determined for the enzyme in the kinetic studies performed. K_M and V_{max} were determined for NADPH and cytochrome c. …

Synthesis, Molecular Docking, And Antitumoral Activity Of Alnustone-Like Compounds Against Estrogen Receptor Alpha-Positive Human Breast Cancer, Kaan Küçükoğlu, Hati̇ce Seçi̇nti̇, Aykut Özgür, Hasan Seçen, Yusuf Tutar

Turkish Journal of Chemistry

Alnustone-like compounds are promising inhibitors for estrogen receptor \alpha (ER-\alpha), which is a novel cancer therapeutic target. Therefore, 10 alnustone-like compounds with substituents at the phenyl rings were synthesized by condensation of 4-phenyl-2-butanones and cinnamaldehydes via in situ enamination. The compounds displayed either protective activity or inhibited cell growth and proliferation of human breast cancer cells. Molecular docking studies indicated that the synthesized compounds interact with ER-\alpha efficiently. In this work, the protective and inhibitive roles of the synthesized compounds were related to their functional groups and to their binding mode of action on ER-\alpha protein. The compounds are potential …

Synthesis, Properties, And Electrochemistry Of A Photochromic Compound Based On Dithienylethene And Prodot, Melek Pamuk Algi, Ati̇lla Ci̇haner, Fati̇h Algi

Turkish Journal of Chemistry

The synthesis, photochromic features, and electrochemistry of a novel material based on dithienylethene (DTE) and 3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (didecyl-ProDOT) units are described. It is noteworthy that 1,2-bis(5-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-2-methylthiophen-3-yl)cyclopent-1-ene can be efficiently switched between open and closed states by light in both solution and in the solid poly(methyl metacrylate) (PMMA) matrix. It is also found that the emission of this novel compound can be switched on and off upon irradiation.

Molecular Docking Analysis And Molecular Dynamics Simulation Study Of Ameltolide Analogous As A Sodium Channel Blocker, Maryam Iman, Atefeh Saadabadi, Asghar Davood

Turkish Journal of Chemistry

Fifteen compounds related to ameltolide with sodium channel inhibitory activity were subjected to a molecular docking study. The chemical structures of all compounds were built using the program HyperChem and conformational studies were performed with a semiempirical method followed by the PM3 method. A docking study was performed using the program AutoDock on all the compounds. To confirm the binding mode of inhibitors, molecular dynamics simulations were performed using GROMACS 4.5.5, based upon the docked conformation of ameltolide. The docking analyses indicated that these compounds interacted mainly with residues II-S6 and III-S6 of NaV1.2 by making hydrogen bonds and (\pi …

Synthesis, Characterization, And Metal Extraction Studies Of A New Macrobicyclic Ligand, Hali̇l Zeki̇ Gök, Yaşar Gök, Esra Eker

Turkish Journal of Chemistry

This article describes the synthesis, characterization, and metal ion binding properties of a new macrobicyclic ligand. Solvent extraction experiments were performed in order to determine the extraction behavior of new macrobicyclic ligand towards selected metal cations. Selective extraction of heavy metals and precious metals is highly demanded due to their toxicity and commercial importance. Based on our experimental results, macrobicyclic ligand 3 demonstrated remarkable affinity towards the Ag^+ ion by 96.7% and 96.9% to the dichloromethane and chloroform phases, respectively. The extraction experiments with macrobicyclic ligand 3 for the Ag^+ ion were repeated at different temperatures to calculate thermodynamic parameters. …

Synthesis, Structural Characterization, And Antimicrobial Efficiency Of Sulfadiazine Azo-Azomethine Dyes And Their Bi-Homonuclear Uranyl Complexes For Chemotherapeutic Use, Abdalla M. Khedr, Fawaz A. Saad

Turkish Journal of Chemistry

Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homonuclear UO_2(II)-complexes were synthesized for potential chemotherapeutic use. The ligands were prepared, starting from the coupling of sulfadiazine dizonium salt with acetylacetone, followed by condensation with ethylenediamine and 1,6-hexanediamine (HL^I and HL^{II}) using a modified literature procedure. The structures of the ligands and their UO_2(II)-complexes were elucidated by conventional and thermal gravimetric analyses, molar conductivity, magnetic susceptibility, and IR, UV-Vis, ^1H NMR, and mass spectra. The analytical and spectral data supported the binuclear formulation of the complexes with a 2:1 metal to ligand ratio and octahedral geometry. The molar …

Revisiting The Biodesulfurization Capability Of Hyperthermophilic Archaeon Sulfolobus Solfataricus P2 Revealed Dbt Consumption By The Organism In An Oil/Water Two-Phase Liquid System At High Temperatures, Gökhan Gün, Yuda Yürüm, Gi̇zem Di̇nler Doğanay

Turkish Journal of Chemistry

The ability of the hyperthermophilic archaeon Sulfolobus solfataricus P2 to grow on organic and inorganic sulfur sources was investigated. A sulfur-free mineral medium was employed with different sources of carbon. The results showed that inorganic sulfur sources display growth curve patterns significantly different from the curves obtained with organic sulfur sources. Solfataricus has the ability to utilize DBT and its derivatives, but it lacks BT utilization. Solfataricus} utilizes DBT at a rate of 1.23 \mu mol 2-HBP h^{-1} g DCW^{-1} even at 78 °C, at which DBT is known to be unstable. After enabling DBT stabilization using a two-phase culture …

Improvement Of Solubility Of Celecoxib By Inclusion In Mcm-41 Mesoporous Silica: Drug Loading And Release, Şahi̇ka Günaydin, Ayşen Yilmaz

Turkish Journal of Chemistry

Celecoxib is a poorly water-soluble nonsteroidal anti-inflammatory drug. Here we report four ordered mesoporous silica MCM-41 supports with different particle size, pore volume, and surface properties to investigate their loading capacity with celecoxib and their release abilities. Spherical MCM-41 mesoporous supports less than 50 nm in diameter were prepared and to compare the effect of the template removal process on morphology of samples, acid extraction and calcination methods were used. Moreover, nearly 500 nm sized rod-shaped MCM-41 mesoporous silica was obtained by changing the template concentration in preparation. Boron doping was performed to determine the effect of a heteroatom on …

Ring Opening And Ring Closure Reactions Of Chromone-3-Carboxylic Acid: Unexpected Routes To Synthesize Functionalized Benzoxocinones And Heteroannulated Pyranochromenes, Magdy Ahmed Ibrahim, Tarik El-Sayed Ali

Turkish Journal of Chemistry

Unexpected routes to synthesize functionalized benzoxocinones and heteroannulated pyranochromenes were achieved via transformations of the \gamma-pyrone ring in chromone-3-carboxylic acid throughout its reactions with some acyclic and cyclic carbon nucleophiles. A key part of the reaction mechanisms is discussed. Structures of the new synthesized products were established on the basis of elemental analysis and spectral data (IR, MS, and ^1H and ^{13}C NMR).

Hplc Fluorescence Determination Of Ochratoxin A Utilizing A Double Internal Standard And Its Application To Poultry Feed, Muzaffer Tunçel, Eli̇f Mi̇ne Öncü Kaya, Ülkü Di̇lek Uysal, Tufan Güray

Turkish Journal of Chemistry

A validated liquid chromatography method employing a fluorescence detector for the determination of ochratoxin A (OTA) was developed with double internal standard and it was applied to ten different poultry feeds. The analysis was performed in an octadecyl silane column using a solvent system [ACN:water:formic acid (50:50:1.25, v/v/v)] by isocratic elution. The flow rate and injection volume were 1 mL min^{-1} and 12 \mu L, respectively. Signals were detected at 278(\lambda_{ex})/315(\lambda_{em}) and 330(\lambda_{ex})/450(\lambda_{em}) nm between 0 and 8, and 8.01 and 20.0 min, respectively. The method was validated with precision, linearity, accuracy, limit of detection, limit of quantification, robustness, and …

Synthesis, Characterization, Biological Studies, And Molecular Modeling Of Mixed Ligand Bivalent Metal Complexes Of Schiff Bases Based On $N$-Aminopyrimidine-2-One/2-Thione, Hati̇ce Gamze Soğukömeroğullari, Tuğba Taşkin Tok, Feyza Yilmaz, İsmet Berber, Mehmet Sönmez

Turkish Journal of Chemistry

New mixed Schiff bases, Cu(II), Co(II), Ni(II), and Mn(II) complexes, were synthesized derived from 5-chloro-2-hydroxyacethophenone and 1-amino-5-benzoyl-4-phenyl-1H-pyrimidine-2-one/thione. These complexes were characterized by elemental analysis, magnetic measurements, molar conductivity, IR, electronic, NMR, and mass spectral studies. All the complexes showed nonelectrolytic behavior. Moreover, the newly synthesized mixed ligand complexes were evaluated for their in vitro antimicrobial efficiency against bacteria and yeast. The compound named Co(L$_{1}$L) had good antifungal activity against Candida species, but no profound antibacterial effect against bacterial strains. In addition, the ground state geometries of the complexes were optimized using a semi-empirical method at PM6 level, which is a …

Synthesis And Biological Evaluation Of Novel Fused Triazolo[4,3-$A$] Pyrimidinones, Ikhlass Abbas, Sobhi Gomha, Mohamed Elneairy, Mahmoud Elaasser, Bazada Mabrouk

Turkish Journal of Chemistry

The reaction of thione 3 or its 2-methylthio derivative 4 with hydrazonoyl halides 5a-l, in the presence of triethylamine, yielded the corresponding triazolo[4,3-$a$]pyrimidin-5(1$H)$-ones 8a-l. The structure of compounds 8a-l was further confirmed by the reaction of 3 with the appropriate active chloromethylenes 11a-c followed by coupling of the products with benzenediazonium chloride to afford the azo-coupling products 6b, f, and j, which were converted in situ to 8b, f, and j. 2-Hydrazinyl-pyrido[3',2':4,5]thieno[3,2-$d$]pyrimidin-4(3$H)$-one (13) was prepared and condensed with different aldehydes 14a-f to give the corresponding hydrazone derivatives 15a-f. Oxidative cyclization of the hydrazones 15a-f give the corresponding triazolo[4,3-$a$] pyrimidin-5(1$H)$-one derivatives …

Synthesis Of Bis-Thiazoles, Bis-Pyrazoles, Bis-Hydrazonates, And Bis-Triazolothiadiazoles Based On Bis-Hydrazonoyl And Bis-Hydrazones, Abdelwahed Sayed

Turkish Journal of Chemistry

A facile synthesis of bis-thiazoles, bis-pyrazoles, and bis-hydrazonates from the reaction of bis-hydrazonoyl dichlorides with different moieties is described. Bis-triazolothiadiazoles were synthesized via oxidative cyclization of bis-hydrazones. Structures of the final product were elucidated by elemental analyses and spectral data.

Green Synthesis Of 2-Amino-7-Hydroxy-4-Aryl-4$H$-Chromene-3-Carbonitriles Using Zno Nanoparticles Prepared With Mulberry Leaf Extract And Zncl$_{2}$, Akbar Mobinikhaledi, Atisa Yazdanipour, Majid Ghashang

Turkish Journal of Chemistry

A highly efficient and environmentally benign protocol for the synthesis of 2-amino-7-hydroxy-4-aryl-4$H$-chromene-3-carbonitrile derivatives in good to high yields (77%-97%) by one-pot three-component coupling reaction of aromatic aldehydes, malononitrile, and resorcinol under reflux condition was developed in aqueous media using ZnO nanoparticles that were prepared in the presence of mulberry leaf extract under mild conditions.

Dinitrogen Reduction On A Polypyrrole Coated Pt Electrode Under High-Pressure Conditions: Electrochemical Impedance Spectroscopy Studies, Di̇dem Balun Kayan, Fati̇h Köleli̇

Turkish Journal of Chemistry

The electrochemical impedance spectroscopy (EIS) responses of a polypyrrole (PPy)-coated platinum electrode were investigated during N$_{2}$-reduction to ammonia in aqueous medium. Kinetic parameters such as film resistance, pore resistance, and double layer capacitance were analyzed as a function of applied potential and polymer film thickness. The relation between kinetic parameters was discussed by combining electrolysis results. It was found that the optimum film thickness of polypyrrole was 0.73 $\mu $m and optimum potential for ammonia synthesis was -0.150 V under 60 bar N$_{2}$-pressure. The impedance responses under these conditions presented the lowest pore resistance value of ca. 2 $\Omega $ …

Two New Coordination Polymers Containing Dicyanidoargentate(I) And Dicyanidoaurate(I): Synthesis And Characterization, And A Detailed In Vitro Investigation Of Their Anticancer Activities On Some Cancer Cell Lines, Ali̇ Aydin, Ahmet Karadağ, Şaban Teki̇n, Nesri̇n Korkmaz, Aslihan Özdemi̇r

Turkish Journal of Chemistry

Two novel cyanido-bridged bimetallic polymeric complexes, [Ni(edbea)Ag$_{3}$(CN)$_{5}$]$_{n} $(C1) and [Ni(bishydeten) Au$_{2}$(CN)$_{4}$]$_{n}$ (C2), where edbea = [2,2$' $-(ethylenedioxy)bis(ethylamine)] and bishydeten = [($N$,$N' $-bis(2-hydroxyethyl) ethylenediamine)] are ligands, were synthesized and characterized by elemental, infrared, and thermal measurement techniques and investigated for their biological activity in cultured cancer cell lines. The results show that both compounds and free anions, [Ag(CN)$_{2}$]$^{-}$ and [Au(CN)$_{2}$]$^{-}$, exhibited very high antiproliferative activity compared to the anticancer drug 5FU against the cancer cell lines tested. The antiproliferative and cytotoxic activities of C1 and C2 were significantly lower than those of free anions, indicating that the extreme cytotoxicity of free …

Kojic Acid In Organic Synthesis, Maryam Zirak, Bagher Eftekhari-Sis

Turkish Journal of Chemistry

The reactions of kojic acid in organic synthesis are reviewed. The aim of this review is to cover the literature up to the end of 2014, showing the distribution of publications involving kojic acid chemistry in the synthesis of various pyrone containing compounds, pyridine and pyridone heterocycles, and also other organic compounds. First, introductory text about the preparation, biological, and industrial applications, and the chemical properties of kojic acid is given. Then its uses in organic synthesis are presented considering the reaction type.

A New And Simple Procedure For The Trace Determination Of Mercury Using Differential Pulse Polarography And Application To A Salt Lake Sample, Güler Somer, A. Cengi̇z Çalişkan, Olcay Şendi̇l

Turkish Journal of Chemistry

A new and simple differential pulse polarographic procedure was established for the trace determination of mercury(II). An indirect method had to be used since no polarographic peak can be observed for its direct determination. According to their standard potentials, the reaction between SO$_{3}^{2-}$ and Hg(II) was suitable. The peak height of sulfite at about -0.70 V (pH 6, 7) was sharp, high, and very reproducible, enabling the accurate determination of low concentrations of Hg(II). It was found that sulfite concentration had to be 3 times larger than mercury at pH 6, in order to have a quantitative reaction. The procedure …

Acid-Free Synthesis Of S-Nitrosothiols At Neutral Ph By Shock-Freezing In Liquid Nitrogen, Dimitrios Tsikas, Anke Böhmer, Arne Trettin, Arslan Arinç Kayaçelebi̇

Turkish Journal of Chemistry

A laboratory method for the acid-free synthesis of S-nitrosothiols (RSNO) from NaNO$_{2}$ and thiols in aqueous buffer of neutral pH is reported. Equimolar amounts of NaNO$_{2}$ and thiol are added to a 100-$\mu $M Na$_{4}$EDTA-containing Na$_{2}$HPO$_{4}$ buffer (100 mM, pH 7.4). Samples are set into liquid nitrogen for 1 min and then thawed to room temperature or in an ice bath. Dependent upon the RSNO, repetition of the procedure may be required. This method may be of particular importance when the classical acid-based method fails or releases harmful gases such as H$_{2}$S.

Synthesis Of 5-Aryl-$N$-(Trichloroacetyl)-1,3,4-Oxadiazole-2-Carboxamide Via Three-Component Reaction Of Trichloroacetyl Isocyanate, ($N$-Isocyanimino)Triphenylphosphorane, And Benzoic Acid Derivatives, Nahid Shajari, Ali Reza Kazemizadeh, Ali Ramazani

Turkish Journal of Chemistry

The three-component reaction of benzoic acid derivatives, ($N$-isocyanimino)triphenylphosphorane, and trichloroacetyl isocyanate in a 1:1:1 ratio in CH$_{3}$CN occurred at room temperature, and the 5-aryl-$N$-(trichloroacetyl)-1,3,4-oxadiazole-2-carboxamide derivatives produced were formed in high yields. The reaction proceeded smoothly and cleanly under mild reaction conditions and no side reactions were observed. The structures of the products were confirmed by IR, $^{1}$H NMR, $^{13}$C NMR, mass spectroscopy, and elemental analysis.