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Hydrazine
Kinds of Hydrazine Terms modified by Hydrazine Selected AbstractsElectrocatalytic Oxidation and Voltammetric Determination of Hydrazine on the Tetrabromo- p -Benzoquinone Modified Carbon Paste ElectrodeELECTROANALYSIS, Issue 5 2007Jahan-Bakhsh Raoof Abstract The electrochemical properties of hydrazine studied at the surface of a carbon paste electrode spiked with p -bromanil (tetrabromo- p -benzoquinone) using cyclic voltammetry (CV), double potential-step chronoamperometry and differential pulse voltammetry (DPV) in aqueous media. The results show this quinone derivative modified carbon paste electrode, can catalyze the hydrazine oxidation in an aqueous buffered solution. It has been found that under the optimum conditions (pH,10.00), the oxidation of hydrazine at the surface of this carbon paste modified electrode occurs at a potential of about 550,mV less positive than that of a bar carbon paste electrode. The electrocatalytic oxidation peak current of hydrazine showed a linear dependent on the hydrazine concentrations and linear analytical curves were obtained in the ranges of 6.00×10,5 M,8.00×10,3 M and 7.00×10,6 M,8.00×10,4 M of hydrazine concentration with CV and differential pulse voltammetry (DPV) methods, respectively. The detection limits (3,) were determined as 3.6×10,5 M and 5.2×10,6 M by CV and DPV methods. This method was also used for the determination of hydrazine in the real sample (waste water of the Mazandaran wood and paper factory) by standard addition method. [source] Barrel Plating Rhodium Electrode: Application to Flow Injection Analysis of HydrazineELECTROANALYSIS, Issue 14 2005Jun-Wei Sue Abstract We introduce here the application of barrel plating technology for mass production of disposable-type electrodes. Easy for mass production, barrel plating rhodium electrode (Rh-BPE) is for the first time demonstrated for analytical application. Hydrazine was chosen as a model analyte to elucidate the electrocatalytic and analytical ability of the Rh-BPE system in pH,7 phosphate buffer solution. Flow injection analysis (FIA) of hydrazine showed a linear calibration range of 25,1000,ppb with a slope and a regression coefficient of 5,nA/ppb and 0.9946, respectively. Twenty-two replicate injections of 25,ppb hydrazine showed a relative standard deviation of 3.17% indicating a detection limit (S/N=3) of 2.5,ppb. The system can be continuously operated for 1 day without any alteration in the FIA signals and is tolerable to the interference of oxalic acid, gelatine, Triton X-100, and albumin for even up to 100 times excess in concentration with respect to 400,ppb hydrazine. Since the fabrication cost of the electrode is cheap, it is thus disposable in nature. Furthermore, barrel plating technique can be extendable to other transition metals for application in many fields of research interest. [source] Synthesis of Pyrazoles by Treatment of 3-Benzylchromones, 3-Benzylflavones and Their 4-Thio Analogues with Hydrazine,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2006Albert Lévai Abstract The synthesis of pyrazoles 13,24 has been accomplished by treatment of 3-benzylchromones 1,5, 3-benzylflavones 6,12 and their 4-thio analogues 25,29 with hydrazine hydrate in hot pyridine. A plausible reaction mechanism for the formation of pyrazoles 13,24 is discussed. A 1H NMR study in [D6]DMSO allowed the presence of both pyrazole annular tautomers to be observed, due to the presence of intramolecular hydrogen bonds in each tautomer (OH--N and NH--O). GIAO/B3LYP/6-311++G** calculations were carried out on some model pyrazoles to provide a theoretical basis for the NMR experimental observations.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis of Pyrazolyl-2-pyrazolines by Treatment of 3-(3-Aryl-3-oxopropenyl)chromen-4-ones with Hydrazine and Their Oxidation to Bis(pyrazoles)EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 22 2004Albert Lévai Abstract The synthesis of several 1-acetyl-3-aryl-5-[3-(2-hydroxyphenyl)pyrazol-4-yl]-2-pyrazolines 3a,3h has been accomplished by treatment of the 3-(3-aryl-3-oxopropenyl)chromen-4-ones 1a,h with hydrazine hydrate in hot acetic acid. The 1-acetyl-3-aryl-5-(3-chromonyl)-2-pyrazolines 2a,2f were also obtained as by-products. Oxidation of the 1-acetyl-4-pyrazolyl-2-pyrazolines 3a,3f with DDQ gave the 3(5)-aryl-5(3)-[3-(2-hydroxyphenyl)pyrazol-4-yl]pyrazoles 5a,5f. The oxidation of the 2-pyrazoline rings was accompanied by N -deacylation. The reaction mechanisms of both transformations are discussed, the first one being supported by experimental results. The structures of all new derivatives were established by NMR and the evidence of prototropic tautomerism is carefully discussed. Theoretical calculations of energies and of the 1H and 13C NMR chemical shifts of the possible tautomeric forms of 5(3)-[3-(2-hydroxyphenyl)pyrazol-4-yl]-3(5)-(4-methoxyphenyl)pyrazole (5c), by B3LYP and GIAO, showed that compounds of this type probably exist as mixtures of two tautomers. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Second Generation CaSH (Camphor Sulfonyl Hydrazine) Organocatalysis.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Alder Reactions, Asymmetric Diels, Isolation of the Catalytic Intermediate Abstract In one step, the well known chiral auxiliary, Oppolzer's camphor sultam, is turned into the new generation camphor sulfonyl hydrazine (CaSH II) organocatalyst. With the primary hydrazine functionality external to the tricyclic structure, CaSH II is active towards ketone substrates in asymmetric Diels,Alder reactions. The iminium intermediate of the catalytic cycle was isolated. When it was put back into the solution reaction system, the same level of yield and stereoselectivity was observed. Based on these observations, we argue that organocatlyst is actually an in situ chiral auxiliary. [source] Metal-Organic Frameworks (MOFs) as Heterogeneous Catalysts for the Chemoselective Reduction of Carbon-Carbon Multiple Bonds with HydrazineADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Amarajothi Dhakshinamoorthy Abstract The as-synthesized metal-organic frameworks (MOFs), particularly that based on aluminium coordinated with benzenedicarboxylic acid, constitute selective catalysts for the reduction of carbon-carbon multiple bonds in alkenes, alkynes and ,,,-unsaturated esters with hydrazine hydrate in acetonitrile under mild conditions. The present protocol enjoys advantages such as convenient reaction conditions and benign, reusable and cost effective catalyst. [source] ChemInform Abstract: Novel Polynuclear Nickel(II) Complex: Hydrazine, Sulfato, and Hydroxo Bridging in an Unusual Metal Hexamer.CHEMINFORM, Issue 35 2010Crystal Structure, Magnetic Properties of [Ni6(N2H4)6 (SO4)4(OH)2(H2O)8] (SO4) (H2O)10. Abstract The title compound is prepared by reaction of NiSO4 and hydrazine in aqueous solution (40 °C, 5 h; yield not given). [source] ChemInform Abstract: The Conversion of Isothiazoles into Pyrazoles Using Hydrazine.CHEMINFORM, Issue 51 2009Heraklidia A. Ioannidou Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: The Conversion of Isothiazoles into Pyrazoles Using Hydrazine.CHEMINFORM, Issue 51 2009Heraklidia A. Ioannidou Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Reaction of 1,5-Diaryl-3-hydroxy-4-methylsulfonyl-3-pyrrolin-2-ones with Urea, Hydrazine, Ethylenediamine, and o-Phenylenediamine.CHEMINFORM, Issue 33 2008V. L. Gein Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Synthesis of Fused Nonaromatic Heterocyclic Systems Based on Dioxolanones (I) and Hydrazine.CHEMINFORM, Issue 45 2007Yu. B. Chudinov Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] N-Isopropylidene-N,-2-nitrobenzenesulfonyl Hydrazine, a Reagent for Reduction of Alcohols via the Corresponding Monoalkyl Diazenes.CHEMINFORM, Issue 28 2007Mohammad Movassaghi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Reaction of Hydrazine and Hydroxylamine Derivatives with Pyrimidinoacetic Acid Esters and Lactones.CHEMINFORM, Issue 20 2007Sergei I. Filimonov Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Reaction of 2-Vinyloxymethyloxirane and 2-(2-Vinyloxyethoxymethyl)oxirane with Hydrazine.CHEMINFORM, Issue 8 2007B. F. Kukharev Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] New Practical Synthesis of Indazoles via Condensation of o-Fluorobenzaldehydes and Their O-Methyloximes with Hydrazine.CHEMINFORM, Issue 8 2007Kirill Lukin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] An Unusual Reaction of (2-Oxo-1,2-dihydro-3H-indol-3-ylidene)acetic Acid Esters with Hydrazine.CHEMINFORM, Issue 11 2006V. O. Kozminykh Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Reaction of 2-Acyl-6-methylbenzo[b]furan-3-acetic Acids Derivatives with Hydrazine.CHEMINFORM, Issue 48 2005Valery S. Tolkunov Abstract For Abstract see ChemInform Abstract in Full Text. [source] Reaction of Aldehydes with Hydrazine in the System Sulfur,Alkali.CHEMINFORM, Issue 19 2003N. V. Russavskaya Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Reactions of Perfluoro(5-aza-4-nonene) with Hydrazine and Some of Its Derivatives.CHEMINFORM, Issue 27 2002G. G. Furin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Reaction with Hydrazine of 2-Alkoxyimino-3-oxobutanoic Acid Esters.CHEMINFORM, Issue 16 2002V. V. Zakharychev Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Reaction of 3,4-Bis(4-methyl-3-furazanylcarbonyl)furoxan with Hydrazine.CHEMINFORM, Issue 4 2001I. V. Tselinskii Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Structures of N - (2,3,4,6-Tetra- O -acetyl-,- D -glycosyl) thiocarbamic Benzoyl HydrazineCHINESE JOURNAL OF CHEMISTRY, Issue 2 2002Shu-Sheng Zhang Abstract The crystal structure of N - (2,3,4,6-Tetra- O -acetyl-,- D -glycosyl)-thiocarbamic benzoyl hydrazine (C22H27N3O9S) was determined by X-ray diffraction method. The hexopyranosyl ring adopts a chair conformation. All the ring substituents are in the equatorial positions. The acetoxyl-methyl group is in synclinal conformation. The S atom is in synperiplanar conformation while the benzoyl hydrazine moiety is anti -periplanar. The thiocarbamic moiety is almost coplanar with the benzoyl hydrazine group. There are two intramolecular hydrogen bonds and one intermolecular hydrogen bond for each molecule in the crystal structure. The molecules form a network structure through intermolecular hydrogen bonds. [source] Reductive Deoximation of Aryloximes into Hydrocarbons by Hydrazine/KOH: A Novel Application of the Wolff,Kishner Reduction.CHEMINFORM, Issue 45 2006H. M. Nanjundaswamy Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Desymmetrization of meso -Bicyclic Hydrazines by Rhodium-Catalyzed Enantioselective HydroformylationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2008Chloée Bournaud Abstract An asymmetric hydroformylation of three meso -bicyclic hydrazines followed by the reduction of the formyl product afforded the corresponding desymmetrized optically enriched hydroxymethyl hydrazines (up to 77.5,%,ee). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Sequential Copper-Catalyzed Rearrangement,Allylic Substitution of Bicyclic Hydrazines with Grignard ReagentsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2009Stefano Crotti Abstract The problem of the synthesis of trans- 1,4-disubstituted hydrazino- and aminocyclopentenes has been resolved by a sequential copper-catalyzed rearrangement,allylic alkylation of 2,3-diazabicyclo[2.2.1]heptenes. The cis -fused 5,5-membered allylic carbazate which is formed in situ by a novel copper(II) triflate [Cu(OTf)2]/(±)-BINAP-catalyzed rearrangement, can be alkylated with a broad spectrum of Grignard reagents with a predominant SN2,-regioselectivity. The N-Boc protecting group proved to be optimal as regards yields, reaction times and regioselectivities. [source] Direct Polymerase Synthesis of Reactive Aldehyde-Functionalized DNA and Its Conjugation and Staining with Hydrazines,ANGEWANDTE CHEMIE, Issue 6 2010Veronika Raindlová In zwei Stufen zu reaktiver Aldehyd-modifizierter DNA: durch Suzuki-Kreuzkupplung halogenierter Nucleosidtriphosphate (dNTPs) mit 4-Formylthiophen-2-boronsäure und Polymerase- vermittelten Einbau der modifizierten Nucleotide in DNA (siehe Schema; PEX=Primerverlängerung, PCR=Polymerasekettenreaktion). Die Bildung von Hydrazonen mit Arylhydrazinen unter wässrigen Bedingungen wurde zum Anfärben der DNA verwendet. [source] ChemInform Abstract: Catalytic Enantioselective Hydrogenation of N-Alkoxycarbonyl Hydrazones: A Practical Synthesis of Chiral Hydrazines.CHEMINFORM, Issue 22 2010Naoki Yoshikawa Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Ligand Control in Enantioselective Desymmetrization of Bicyclic Hydrazines: Rhodium(I)-Catalyzed Ring-Opening versus Hydroarylation.CHEMINFORM, Issue 19 2009Jane Panteleev Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Carbohydrate-Based Tolylsulfonyl Hydrazines: Effective Catalysts for the Mannich Reaction and the Syntheses of Bisindolylalkanes in Water.CHEMINFORM, Issue 40 2008Peng Wu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Direct One-Step Synthesis of Azaheterocyclic Phosphonates from Diethyl ,-Chloro-1-alkynylphosphonates and Hydrazines.CHEMINFORM, Issue 33 2007Abdullatif Azab Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] | |||||||||||||||||||||||||||||||||||||