• 제목/요약/키워드: phenyl

검색결과 1,806건 처리시간 0.022초

Kinetic Studies on Bromine-Exchange Reactions of Antimony Tribromide with $\alpha$-Phenyl-n-butyl and $\alpha$-Phenyl-i-butyl Bromides in Nitrobenzene$^\dag$

  • Rhyu, Sok-Hwan;Choi, Sang-Up
    • Bulletin of the Korean Chemical Society
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    • 제8권5호
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    • pp.408-414
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    • 1987
  • The rate of bromine-exchange reaction between antimony tribromide and ${\alpha}-phenyl-n-butyl$ bromide in nitrobenzene has been determined, using antimony tribromide labelled with Br-82. The results indicate that the exchange reaction follows the first-order kinetics with respect to the organic bromide, and either the second- or first-order kinetics with respect to antimony tribromide depending on its concentration. The third-order rate constant obtained was 7.50 ${\times}10^{-2}l^2mol^{-2}s^{-1}$ at 28$^{\circ}$C. Similar study on the bromine-exchange reaction between antimony tribromide and ${\alpha}$-phenyl-i-butyl bromide has also been carried out. The results of the study show the same kinetic orders as the ones observed with $\alpha$-phenyl-n-butyl bromide. The third-order rate constant observed was 2.40 ${\times} 10^{-2} l^2mol^{-2}s^{-1}$ at 28$^{\circ}$C. The activation energy, the enthalpy of activation and the entropy of activation for the two exchange reactions mentioned above have been determined. The reaction mechanisms for the exchange reactions are discussed.

Syntheses and Potentiometric Properties of Polyethers Containing Thiazole and Oxazole Derivatives

  • 최준혁;고영국;권일전;김홍석;박현주;김상진;차근식;남학현
    • Bulletin of the Korean Chemical Society
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    • 제20권5호
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    • pp.581-586
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    • 1999
  • A series of polyethers containing the thiazole or oxazole subcyclic moiety have been synthesized. Reaction of 2-aryl-4-hydroxymethylthiazole with tetra- and pentaethylene glycol di-p-tosylate in THF provided corresponding α,ω-bis[2'-aryl-4'-methylthiazole]polyethylene glycol in good yields. Similar treatment of 2-phenyl-4-hydroxymethyloxazole 7 and 2-phenyl-5-hydroxymethyloxazole 8 with tetraethylene glycol di-p-tosylate yielded the corresponding 1,13-bis [2'-phenyl-4'-methyloxazole]tetraethylene glycol 16 and 1,13-bis[2'-phenyl-5'-methyloxazole]tetraethylene glycol 17 in 69 and 43% yields in respectively. The potentiometric properties of PVC-based ion selective membranes containing 66 wt% o-nitrophenyloctyl ether (NPOE) and 4 wt% polyethers 9-17 have been examined. The membranes containing thiazole and oxazole polyether derivatives exhibited high selectivity toward silver (I) ion. It was observed that the response slopes of the electrodes to silver ion vary with the length of polyether chain linking two thiazole subcyclic moiety. Potentiometric data suggest that the number of ether units, CH2OCH2, for phenylthiazole derivatives be greater than 5 to result in near-Nernstian response. However, the response behaviors of the membrane electrodes based on phenyloxazole podands 16 and 17, which have different orientation, were correspondingly similar to those of the electrodes based on phenylthiazole podands 9 and 10. On the other hand, the ISEs based on thiazole polyether derivatives with different terminal substituents, e.g., phenyl 10, naphtyl 14, and thienyl 15, except that with pyridyl 12, exhibited little difference in their potentiometric properties.

Some Reactions of 3-Methyl-5-oxo-1-phenyl-Δ2-pyrazoline-4-thiocarbohydrazide

  • Kandeel, Maymona M.;Abbady, Mohamed S.;Youssef, Mohamed Salah K.
    • Bulletin of the Korean Chemical Society
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    • 제23권1호
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    • pp.41-47
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    • 2002
  • The reactions of 3-methyl-1-phenyl-5-oxo-${\Delta}^2$-pyrazoline-4-thiocarbohydrazide towards phenyl isothiocyanate, sodium nitrite, cyclohexanone, aromatic aldehydes, and carbon disulphide has been studied. The Vilsmeier-Haack reaction has been applied on 4-substituted pyrazolone derivatives.

Formamidine류의 합성 및 살균성 (Studies on the synthesis and bactericidal activity of formamidines)

  • 이계주;장반섭
    • 약학회지
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    • 제17권1호
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    • pp.17-20
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    • 1973
  • Six novel compounds of N,N-dimethyl-N'-(6-substituted-2-benzothiazolyl) formamidines nad six novel compounds of N, N-dimethyl-N'-(substituted-phenyl)formamidines were synthesized. They were evaluated fro their bactericidal activities aginst Salmonella typhoso, Escherichia coli, Vibrio cholera, Staphyloccus aureus, Sarcina lutea and for their fungicidal activities against Saccharomyces cereviseae, Candida albicans. It was found that these compounds were considerably more active than phenol, especially against Vibrio cholera, and N, N-dimethy-N'-(4-methyl-phenyl_formamkidine, N, N-dimethyl-N'-(2-methyl-4-bromo-phenyl)formanidine showed most potent bactericidal activities.

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2-phenyl-N-methyl-l,3-thiazolium Perchlorate 유도체의 합성 및 가수분해 (Synthesis and hydrolysis of 2-phenyl-N-methyl-1,3-thiazolium Perchlorate derivatives.)

  • 한만소;이소영
    • 한국응용과학기술학회지
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    • 제15권2호
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    • pp.93-99
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    • 1998
  • 2-phenyl-N-methyl-1,3-thiazolium perchlorate(PTP)derivatives were synthesized via addition and substitution reactions. PTP was hydrolyzed under aqueous hydrochloride. The structures of the compounds were conformed by N.M.R.,I.R., and elemental analysis.

2 위치가 치환된 5-니트로 Benzimidazole 유도체들의 Topoisomerase I 억제 활성 (Topoisomerase I Inhibition of 2-Substituted 5-Nitrobenzimidazoles)

  • 권민진;;김정선
    • 약학회지
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    • 제47권3호
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    • pp.125-129
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    • 2003
  • A series of 2-phenyl-5-nitrobenzimidazoles substituted at the para positon of the 2-phenyl moiety was synthesized & evaluated for their activity to inhibit topoisomerase I. The structure-activity relationship study revealed that neither the electronic nor lipophilic parameters were related to the topoisomerase I inhibition. A strict spatial requirement seems to be present for retention of topoisomerase I inhibition activity.

Synthesis of 4'α-C Phenyl-Branched Carbocyclic Nucleoside Using Ring-Closing Metathesis

  • Hong, Joon-Hee;Ko, Ok-Hyun
    • Bulletin of the Korean Chemical Society
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    • 제24권9호
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    • pp.1289-1292
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    • 2003
  • An efficient synthetic route for preparing novel $4'{\alpha}$-C phenyl branched carbocyclic nucleoside is described. The installation of phenyl group at the $4'$-position of carbocyclic nucleoside was successfully accomplished via a sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM) beginning from simple ketone such as 2-hydroxy acetophenone.