• Title/Summary/Keyword: Nitrobenzenes

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Electrochemical Reduction of Nitrobenzene and Substituted Nitrobenzenes on Lead Electrode

  • Chon, Jung-Kyoon;Paik, Woon-Kie
    • Bulletin of the Korean Chemical Society
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    • v.2 no.1
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    • pp.1-8
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    • 1981
  • Electrochemical reduction of nitrobenzene and substituted nitrobenzenes on lead electrode was studied by galvano-static measurements and cyclic voltammetry in basic ethanol-water solvents. Nitroso compounds or hydroxylamines were detected as the main reduction product depending on the potential. Mechanisms of production and further reduction of substituted and unsubstituted nitrosobenzenes are deduced from Tafel slope, pH dependence and reaction order. The reduction of most of the substituted nitrobenzenes to corresponding nitrosobenzene derivatives seemed to follow the reaction mechanism of nitrobenzene reduction with a few exceptions. A Hammett type relationship between the magnitude of the reduction current and the kinds of substituents was found with the ${\rho}$ value of 0.54.

Synthesis of Azobenzene Derivatives via Controlled Potential Cathodic Electrolysis (조절전위법 음전극 유기반응을 이용한 아조벤젠 유도체들의 합성)

  • Kim Byeong Hyo;Choi Yong Rack;Kim Dae Ho;Han Rongbi;Baik Woonphil;Jun Young Moo
    • Journal of the Korean Electrochemical Society
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    • v.2 no.4
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    • pp.209-212
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    • 1999
  • Using an H-type divided cell, reductive coupling reaction of nitroarene toward azobenzenes in a mild condition was successfully accomplished by the controlled potential cathodic electrolysis reaction. Optimum reaction potential of each reaction was determined based on cyclic voltammetric behavior in methanol solution at Pb or Pt cathode, and Pt anode. In most cases, reductive coupling reactions were successful with excellent yields regardless of the position and the character of the substituents.

Reaction Conditions and Mechanism of Electrolytic Reduction of Nitrobenzene (니트로벤젠의 전해환원 반응 조건과 메카니즘)

  • Chon Jung Kyoon;Paik Woon Kie
    • Journal of the Korean Chemical Society
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    • v.21 no.6
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    • pp.404-412
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    • 1977
  • Electrochemical reduction of nitrobenzene (${\phi}NO_2$) and its derivatives on Pb electrode was studied by means of galvanostatic measurements and coulometric electrolysis in ethanol-water solvent. In acidic solutions phenylhydroxyl amine and aniline ethanol-water solvent. In acidic solutions phenylhydroxyl amine and aniline were produced while nitrosobenzene and coupled products such as azo-and hydrazobenzene were produced in basic solutions. Nitrosobenzene (${\phi}NO$) was not found to be an intermediate in the reduction reactions of ${\phi}NO_2$ in acidic solutions. No direct coupling between ${\phi}NO\;and\;{\phi}NHOH$ was observed to occur in the electrolyte solutions used. Mechanisms of the production of phenylhydroxylamine and nitrosobenzene are deduced from Tafel slope, pH dependence and reaction order with respect to nitrobenzene. Mechanism for the reduction of substituted nitrobenzenes seems to be identical to that of nitrobenzene.

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Studies on the Preparation of Organic Compounds Labelled by $^{38}Cl$.(I) - Inorganic Yields of $^{38}$ Cl in Szilard Chalmer Reaction of Aromatic Chloro Derivatives

  • Kim, You-Sun
    • Nuclear Engineering and Technology
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    • v.5 no.1
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    • pp.44-54
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    • 1973
  • In order to clarify an effective procedure of labelling organic chloro compounds by $^{38}$ Cl, phenyl chloro derivatives(7 kinds), chloro nitrobenzenes(6 kinds), chloro anisoles(2 kinds), chloro anilines(3 kinds), chloro toluenes(3 kinds), benzyl cholorides(4 kinds), and other comparing samples(3 kinds) were irradiated in the TRIGA Mark-II research reactor and the inorganic $^{38}$ Cl yields were compared with the irradiation times after extracting the inorganic portion with an aqueous solution of alkali. It was found that the relative change between the inorganic $^{38}$ Cl yield and the irradiadiation time depends a great deal on the state of the sample, and a solid sample gave a lower and steady inorganic yield. The inorganic $^{38}$ Cl yield was decreased in the order of phenyl chloro derivatives < chloro tol uene$^{38}$ Cl yield of homo functional compounds and the number of chlorine atoms on the benzene ring. Generally, poly chloro substituted derivatives could give a higher yield than those of less chloro substituted. The results were discussed and the feasibility of these results for labelling purpose was criticized.

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