• 제목/요약/키워드: Nucleophilic addition

검색결과 138건 처리시간 0.022초

4'-[N-(9-Acridinyl)]-1'-(N-methanesulfonyl)-3'-methoxyquinonediimide에 대한 Thiophenol 유도체의 친핵성 첨가물의 합성에 관한 연구 (Synthetic Studies on the Nucleophilic Adducts of Thiophenol Derivatives to 4'-[N-(9-Acridinyl)]-1'-(N-methanesulfonyl)-3'-methoxyquinonediimide)

  • 김태린;정동인;편상용
    • 대한화학회지
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    • 제40권8호
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    • pp.565-570
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    • 1996
  • 4'-[N-(9-acridinyl)]-1'-(N-methanesulfonyl)-3'-methoxyquinonediimide(AMQD, 5)를 간편하고 효율적인 새로운 방법으로 얻었으며, AMQD에 thiophenol 유도체를 반응시켜 6종류의 새로운 첨가 생성물(6a-6f)들을 합성하였다. 이 화합물들의 구조는 원소분석, Mass, IR 및 NMR 스펙트라 등에 의하여 확인되었다.

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치환염 벤조일과 파라니트로아닐린과의 친핵반응에 미치는 용매효과에 관한 연구 (Solvent Effect in Nucleophilic Reactions of Substituted Benzoyl Chlorides with p-Nitroaniline)

  • 김왕기
    • 대한화학회지
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    • 제18권4호
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    • pp.251-258
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    • 1974
  • 아세톤, 아세토니트릴, 메탄올, 에탄올 등의 용매에서 치환염 벤조일과 파라니트로아닐린과의 친핵치환반응에 대한 속도상수를 전기 전도도법으로 구하고 활성화 파라미터를 계산하였다. 결과로 반양성자 용매보다는 양성자성 용매에서 반응속도가 빨랐고 같은 성질의 용매에서는 유전상수가 큰 쪽이 반응이 더 빨랐으며 각 용매에 있어서의 Hammett도시는 정의 기울기를 가진 직선을 나타내었으며, 반응은 첨가-제거 메카니즘으로 일어났다.

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Synthesis and Antiviral Evaluation of Novel Methyl Branched Cyclopropyl Phosphonic Acid Nucleosides

  • Kim, Jin-Woo;Ko, Ok-Hyun;Hong, Joon-Hee
    • Archives of Pharmacal Research
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    • 제28권7호
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    • pp.745-749
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    • 2005
  • A simple synthetic route for the synthesis of novel methyl branched cyclopropyl phosphonic acid nucleosides is described. The characteristic cyclopropyl moiety 8 was constructed by employing Simmons-Smith reaction as a key step. The condensation of mesylate 11 with natural nucleosidic bases (A,C,T,U) under standard nucleophilic substitution conditions ($K_2CO_3$, 18-Crown-6, DMF) and after subsequent hydrolysis resulted in the formation of target nucleosides, 16, 17, 18, and 19. In addition, the antiviral evaluations of the synthesized nucleotides against various viruses were also performed.

2,4-Diamino-7-phenyl-6-methythiopteridine 합성에 관한 연구 (A Study on the Preparation of 2,4-Diamino-7-Phenyl-6-Mehylthiopteridine)

  • 박내정;김명웅;이종찬
    • 한국응용과학기술학회지
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    • 제4권1호
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    • pp.61-66
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    • 1987
  • 2,4,6-Triamino-5-nitrosopyrimidine was prepared using malononitrile and guanidine carbonate, and acetylated refluxing in acetic acid with acetic anhydride in order to activate the nitroso group for nucleophilic attack. Nucleophilic attack of phenylpyrimidium bromide on the nitroso group of 2,4,6-triacetamido-5-nitrosopyrimidine gave the intermediate, which lost pyrdidine to give the nitrone derivative. Addition of the methanethiol anion to nitrone gave 2,4-diacetamido-7-phenyl-6-methylthiopteridine which was hydrolyzed to give 2,4-diamino-7-phenyl-6-methylthiopteridine. Spectral data (IR, M.S, NMR) were provided to identify the reaction products during synthesis.

Cross-interaction Constants in the Nucleophilic Reactions of Carbonyl Compounds Involving a Tetrahedral Intermediate

  • Lee, Ik-Choon
    • Bulletin of the Korean Chemical Society
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    • 제15권11호
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    • pp.985-990
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    • 1994
  • Cross-interaction constants, ${\rho}^e_{XY}$, ${\rho}_{YZ}$ and ${\rho}_{XZ}$ are defined using observed rate constant, k_N=(k_1/k_{-1})k_2=Kk_2$, for the stepwise carbonyl addition reactions involving the rate-limiting breakdown of a tetrahedral intermediate $(T^{\pm})$. Abundant experimental evidence in the literature enables us to determine signs for the three constants for such mechanism, ${\rho}^e_{XY}$>0, ${\rho}_{YZ}$<0 and ${\rho}_{XZ}$0. These are in contrast to those for the concerted $S_N2$ mechanism, ${\rho}_{XY}$<0, ${\rho}_{YZ}$>0 and ${\rho}_{XZ}$, and provide useful mechanistic criteria. In the light of these criteria, mechanisms of some nucleophilic reactions of carbonyl compounds are re-examined.

$\alpha$-(n-Butyl)-N-Phenylnitrone 유도체에 대한 Sodium Thiophenoxide의 친핵성 첨가반응 메카니즘과 그의 반응 속도론적 연구 (Kinetics and Mechanism of Nucleophilic Addition of Sodium Thiophenoxide to $\alpha$-(n-Butyl)-N-Phenylnitrone Derivatives)

  • 이광일;이석우;곽천근;김영주;노승일;이기창
    • 대한화학회지
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    • 제38권6호
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    • pp.442-448
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    • 1994
  • ${\alpha}$-(n-Butyl)-N-Phenylnitrone 유도체의 첨가 반응속도상수를 25^{\circ}C$의 수용액에서 자외선 분광광도법으로 측정하여 넓은 pH범위에서 잘 맞는 반응속도식을 유도하였다. 첨가반응생성물은 ${\alpha}$-phenylthiobutylidene-aniline이었으며, 첨가반응속도상수 측정과 반응속도식의 유도, 일반기염 효과, 치환기 효과 및 최종생성물의 결과로부터 반응 메카니즘을 제안하였다. 즉, pH 3.0 이하에서는 티오페놀의 첨가로 반응이 시작되며, pH 3.0∼10.0에서는 티오페놀과 티오페녹시드 음이온이 경쟁적으로 첨가되어 진행되며, pH10.0이상에서는 티오페녹시드 음이온의 첨가에 의해서 반응이 진행된다.

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酸性溶煤 속에서의 $\beta$-Mercaptan에 대한 親核性 添加反應에 관한 硏究 (III) n-Propylmercaptan 및 tert-Butylmercaptan 과의 반응 (The Kinetics and Mechanism of Nucleophilic Addition of Mercaptan to a ${\beta}$-Nitrostyrene in Acidic Media(III) n-Propylmercaptan and tert-Butylmercaptan)

  • 박옥현;김태린
    • 대한화학회지
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    • 제12권4호
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    • pp.177-183
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    • 1968
  • 親核性 添加反應性에 있어서의 mucleophile의 反應性을 정량적으로 연구하고자 前報에 이어 여러 pH에서 3,4-methylenedioxy-$\beta$-nitrostyrene에 n-propyl- 과 tert-butylmercaptan을 첨가시켜 그의 添加反應速度常數를 측정한 결과 n-propylmercaptide ion과 tert-butylmercaptide ion에 대해 각각 $1.26{\times}10^8$$3.98{\times}10^6\;M^{-2},\;sec^{-1}$를 얻었으며, 또 n-propyl 및 tert-butylmercaptan 분자의 添加反應速度常數로서 $7.07{\times}10^{-3}$$1.5{\times}10^3\;M^{-1},\;sec^{-1}$을 각각 얻었다. 한편 염기성 뿐만 아니라 산성용매 속에서도 그의 應速 메카니즘을 잘 설명할 수 있는 全體應速度式을 구하였다.

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Synthesis and Antiviral Evaluation of Novel Acyclic Nucleosides

  • Hong, Joon-Hee;Ko, Ok-Hyun
    • Bulletin of the Korean Chemical Society
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    • 제24권9호
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    • pp.1284-1288
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    • 2003
  • A very short and concise synthetic route for a novel acyclic version of d4T is described. The required quaternary carbon was successfully installed using a [3,3]-sigmatropic rearrangement. The condensation of the mesylates 16-18 with an adenine base under standard nucleophilic substitution conditions ($K_2CO_3$, 18-Crown- 6, DMF) in addition to deblocking afforded the target acyclic nucleosides 22-24. In addition, the antiviral evaluations against various viruses were performed.