共查询到20条相似文献,搜索用时 15 毫秒
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A. A. Avetisyan I. L. Aleksanyan L. P. Ambartsumyan 《Russian Journal of Organic Chemistry》2008,44(5):723-727
By a reaction of 2-methyl-4-chloroquinolines with o-mercaptoaniline under various conditions synteses were performed of substituted in the benzene ring 4-[(2-aminophenyl)thio]-2-methylquinolines and (4E)-4-[(2-mercaptophenyl)imino]-2-methyl-1,4-dihydroquinolines that were respectively by isomerization or rearrangement converted into 4-[(2-mercaptophenyl)amino]-2-methylquinolines. 相似文献
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Moghaddam AB Ganjali MR Norouzi P Latifi M 《Chemical & pharmaceutical bulletin》2006,54(10):1391-1396
This is an environmentally friendly method in the field of electroorganic reactions under controlled potential electrolysis, without toxic reagents at a carbon electrode in an undivided cell which involves the (EC) mechanism reaction and comprises two steps alternatively; (i) electrochemical oxidation and (ii) chemical reaction. In particular, the electrochemical oxidation of 4-tert-butylcatechol, 4-methylcatechol and 2,3-dihydroxybenzoic acid in the presence of 2-phenyl-1,3-indandione has been studied in a water-acetonitrile (90 : 10) mixture. The research includes the use of a variety of experimental techniques, such as cyclic voltammetry, controlled-potential electrolysis, and spectroscopic identification of products (FT-IR, (1)H-NMR, and MS spectrometry). 相似文献
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Summary The application of the named compound for the spectrophotometric determination of scandium is described. The effects due to pH, reagent concentration, time and diverse ions are reported. Beer's law is obeyed and the molar absorbance coefficient at 555 nm is 1.55×104. By using a cupferron extraction prior to analysis, the procedure is quite selective.
Spektrophotometrische Bestimmung von Scandium mit Dinatrium-3-hydroxy- 4-[(6-methyl-2-pyridyl)azo]-2,7-naphthalindisulfonat-N-oxid
Zusammenfassung Die Anwendung der genannten Verbindung für die spektrophotometrische Bestimmung von Scandium wurde beschrieben. Der Einfluß des pH, der Reagenskonzentration, der Zeit und verschiedener Ionen wurde untersucht. Das Beersche Gesetz wird befolgt, der molare Absorptionskoeffizient bei 555 nm beträgt 1,55×104. Nach vorhergehender Cupferron-Extraktion ist das Verfahren selektiv.相似文献
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Summary The synthesis and characterization of disodium 3-hydroxy-4-[(6-methyl-2-pyridyl)azo]-2, 7-naphthalenedisulfonateN-oxide and its application to the spectrophotometric determination of trace amounts of copper are described. The effects due to pH, time, reagent concentration and diverse ions are reported. The reagent exhibits good specificity for copper. Beer's law is obeyed and the molar absorbance coefficient at 536 nm is 1.8×104.
Die spektrophotometrische Bestimmung von Kupfer mit Dinatrium-3-hydroxy-4-[(6-methyl-2-pyridyl)azo]-2, 7-napbthalindisulfonat-N-oxid
Zusammenfassung Die Synthese und die Eigenschaften von Dinatrium-3-hydroxy-4-[(6-methyl-2-pyridyl)azo]-2, 7-naphthalindisulfonat-N-oxid sowie dessen Anwendung zur spektrophotometrischen Bestimmung von Kupferspuren wurden beschrieben. Die Einflüsse von pH, Zeit, Reagenskonzentration und von verschiedenen Ionen wurden angegeben. Das Reagens zeigt gute Spezifität gegenüber Kupfer. Das Beersche Gesetz wird befolgt. Der molare Extinktionskoeffizient bei 536 nm beträgt 1,8·104.相似文献
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Summary The application of the reagent for the spectrophotometric determination of traces of zirconium is described. The effects due to acid concentration, reagent concentration, time and diverse ions are reported. Beer's law is obeyed and the molar absorbance coefficient at 577 nm is 3.2×104.
Die spektrophotometrische Bestimmung von Zirkonium mit Natrium-3-hydroxy-4-[(6-methyl-2-pyridyl) azo]-2,7-naphthalindisulfonat-N-oxid
Zusammenfassung Die Anwendung des genannten Reagens auf die spektrophotometrische Bestimmung von Zirkoniumspuren wurde beschrieben. Der Einfluß der Säurekonzentration, der Reagenskonzentration, der Zeit und verschiedener Fremdionen wurde untersucht. Das Beersche Gesetz wird befolgt; der molare Extinktionskoeffizient bei 577 nm beträgt 3,2 · 104.相似文献
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Alunni S Del Giacco T De Maria P Fifi G Fontana A Ottavi L Tesei I 《The Journal of organic chemistry》2004,69(10):3276-3281
Catalysis of the beta-elimination reaction of N-[2-(4-pyridyl)ethyl]quinuclidinium (1) and N-[2-(2-pyridyl)ethyl]quinuclidinium (2) by Zn(2+) and Cd(2+) in OH(-)/H(2)O (pH = 5.20-6.35, 50 degrees C, and mu = 1 M KCl) has been studied. In the presence of Zn(2+), the elimination reactions of both isomers occur from the Zn(2+)-complexed substrates (C). The equilibrium constants for the dissociation of the Zn(2+)-complexes are as follows: K(d) = 0.012 +/- 0.003 M (isomer 1) and K(d) = 0.065 +/- 0.020 M (isomer 2). The value of k(C)(H2O) for isomer 1 is 4.81 x 10(-6) s(-1). For isomer 2 both the rate constants for the "water" and OH(-)-induced reaction of the Zn(2+)-complexed substrate could be measured, despite the low concentration of OH(-) in the investigated reaction mixture [k(C)H2O)= 1.97 x 10(-6) s(-1) and k(C)(OH-)= 21.9 M(-1) s(-1), respectively]. The measured metal activating factor (MetAF), i.e., the reactivity ratio between the complexed and the uncomplexed substrate, is 8.1 x 10(4) for the OH(-)-induced elimination of 2. This high MetAF can be compared with the corresponding proton activating factor (Alunni, S.; Conti, A.; Palmizio Errico, R. J. Chem. Soc., Perkin Trans. 2 2000, 453), PAF = 1.5 x 10(6) and is in agreement with an E1cb irreversible mechanism (A(xh)D(E)* + D(N)) (Guthrie, R. D.; Jencks, W. P. Acc. Chem. Res. 1989, 22, 343). A value of k(C)(H2O)>or= 23 x 10(-7) s(-1) is estimated for the Cd(2+)-complexed isomer 2, while catalysis by Cd(2+) has not been observed for isomer 1. 相似文献
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Yuri V. Ostapiuk Mykola D. Obushak Vasyl S. Matiychuk Marek Naskrent Andrzej K. Gzella 《Tetrahedron letters》2012,53(5):543-545
It was found that the reaction of 2-chloroacetamido/chloropropioamido-5-benzylthiazole with potassium thiocyanate gave, via rearrangement, 2-[(5-benzyl-1,3-thiazol-2-yl)imino]-1,3-thiazolidin-4-ones. 相似文献
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The early stages of the polymerization of 2-[(methacryloyloxy)ethyl]trimethyl ammonium chloride (MADQUAT) in aqueous solution were studied by pulse radiolysis. The rate constant of the reaction of this monomer with OH√ and hydrated electron was measured as 1.5×1010 and 2.2×1010 dm3mol−1s−1, respectively. The absorption spectrum of the OH√ adduct to MADQUAT molecule appeared to have a maximum at 290 nm. Its decay depends on the monomer concentration. The shape and maximum of the absorption spectrum of electron adduct to the monomer depend on pH of the solution. In acidic solution, radical anion is formed. It subsequently undergoes reversible protonation giving spectrum with a maximum below 260 nm. In basic solution the spectrum has a maximum at 290 nm. In this case irreversible protonation takes place at the β-carbon atom, giving an -centred carbon radical. 相似文献
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A facile method for the synthesis of 3-amino-5-(2-pyridyl)-1,4-benzodiazepin-2-ones (8) mediated by benzotriazole is described. The synthesis and optical resolution of the product by fractional crystallisation proceeds in high yield, under mild conditions and without recourse to toxic reagents or chromatographic separations and hence is amenable to the large scale preparation of these important precursors to potent CCK receptor ligands. 相似文献
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Electrochemical synthesis of 4-morpholino-2-arylsulfonyl-benzamines was carried out by the electrochemical oxidation of 4-morpholinoaniline in the presence of arenesulfinic acids at a carbon electrode, in aqueous solution. Our voltammetric data indicate that electrochemically generated p-quinone-diimine participates in Michael type addition reaction with arenesulfinic acids and via an EC mechanism converts to the title products. This method provides a green, one-pot procedure for the synthesis of 4-morpholino-2-(arylsulfonyl)benzenamines of potential biological significance. 相似文献
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Prosochkina T. R. Tyurina L. A. Kantor E. A. Murza M. M. Shestakova R. G. 《Russian Journal of General Chemistry》2002,72(9):1444-1445
A computer analysis of the relationship between the structure and mesomorphic activity and a search for potentially mesomorphic compounds in the series of azomethines containing a dihydropyranyl fragment, 4'-[(5,6-dihydro-4-methyl-2H-pyran-5-yl)amino]benzylidene-4-alkoxyanilines, were performed using the SARD (Structure Activity Relationship Design) system. The structural fragments exerting positive and negative effects on the manifestation of mesomorphism were revealed. The mesomorphic activity of the training structures and the extent of their similarity with the hypothetical standard of the activity were evaluated. The predictions show 70% agreement with the experiment. 相似文献
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Yun-Long Shi Ling Wang Chao Qian Ming Tao Zu-Tai Liao Xin-Zhi Chen 《Chemical Papers》2015,69(9):1237-1243
A new, practical and cost-effective route for scalable synthesis of 2-[(4-dodecyloxyphenyl)sulfonyl] butanoic acid, a key intermediate of a new cyan dye-forming coupler containing a sulfone group, was developed by adopting phenol as the starting material. The synthesis was accomplished in five steps with etherification, chlorosulfonation, reduction, nucleophilic reaction by C-S coupling and hydrolyzation. An important objective of the new synthetic route was the synthesis of 2-[4-(dodecyloxyphenyl)sulfonyl]butanoate. Overall yield obtained at optimized conditions increased to 66 %. The synthetic strategy was proven to be a process enabling rapid delivery of the target product with high purity. 相似文献
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S. G. Krivokolysko V. D. Dyachenko V. P. Litvinov 《Chemistry of Heterocyclic Compounds》1997,33(5):583-586
Condensation of acetoacetic acid anilide, 4-pyridyl aldehyde, cyanothioacetamide and N-methylmorpholine gave N-methylmorpholinium 6-methyl-4-(4-pyridyl)-5-phenylcarbamoyl-3-cyano-1,4-dihydropyridine-2-thiolate from which were obtained the corresponding substituted pyridinethiones, 2-alkylthio-1,4-dihydropyridines and 3-amino-2-benzoyl-6-methyl-4-(4-pyridyl)-5-phenylcarbamoylthieno[2,3-b]pyridine.T. G. Shevchenko Lugansk Pedagogical Institute, Lugansk 348011. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 672–675, May, 1997. 相似文献