• Title/Summary/Keyword: oxime-ester

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A Charge-Transfer Effect in Solid Phase Peptide Synthesis: Unsusally High Reactivity in Peptide Bond Formation between p-Nitrobenzophenone Oxime Resin Ester and Amino Acid 4-(Methylthio)phenyl Ester

  • Park, Dong-Hyun;Jung, Jae-Kyu;Lee, Yoon-Sik
    • Bulletin of the Korean Chemical Society
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    • v.9 no.6
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    • pp.394-398
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    • 1988
  • Unusually high reactivity was found in peptide bond formation between p-nitrobenzophenone oxime resin (I) ester and amino acid 4-(methylthio)phentyl (MTP) esters. A charge-transfer complex between the two phenyl rings of the oxime resin (I) and the incoming amino acid MTP esters was considered to be responsible to accelerate the aminolysis reaction of the peptide oxime resin ester. Several di-, tri-, and pentapeptide fragments for preparing enkephalin and glutathione oligomers were successfully prepared in short times.

Synthesis and Antifungal Activity of 1,3-substituted-5-chloropyrazole-4-carboxylic acid Oxime Esters (1,3-치환-5-chloropyrazole-4-carboxylic acid oxime ester의 합성과 살균력)

  • Kim, Yong-Whan;Park, Chi-Hyun;Choi, Weon-Seok;Kwon, Young-Chil;Park, Chang-Kyu
    • Applied Biological Chemistry
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    • v.32 no.4
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    • pp.401-407
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    • 1989
  • A series of novel 1,3-substituted-5-chloropyrazole-4-carboxylic acid oxime esters was synthesized. Their chemical strictures were elucidated on $^1H,\;^{13}C-NMR$ and IR spectra, Fifteen such compounds were screened for their antifungal activity against R. solani, P. oryzae, B. cinerea, P. graminearum, P. capsici and G. cingulata. The results showed that pyrazole-oxime esters with electron withdrawing groups(III, XIII, XIV) had better biological activities than these with electron releasing groups.

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A Study on Kinetic Model for the Formation of 5-methyl-4-imidazolecarboxylic Acid Ester (5-methyl-4-imidazolecarboxylic Acid Ester 연속합성의 반응속도론 및 특성 연구)

  • Cho, Wook-Sang;Park, Sang-Jin;Kim, Hak-Hee
    • Applied Chemistry for Engineering
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    • v.5 no.6
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    • pp.1062-1067
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    • 1994
  • The chemistry of 5-methyl-4-imidazolecarboxylic acid ester synthesis involves three distinct reaction steps. Of these the rate of formation of diketone was found to be a function of oxime and HCl concentration and temperature by the batch experiment. The decomposition of diketone was found to be a slow process whereas temperature was the only variable to affect it significantly. An empirical rate expression for the net formation of diketone fits the experminetal data satisfactorily. The principal objectives of this study are to study the kinetics of the diketone formation reaction and to develop the empirical rate expression.

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Preliminary studies on Insecticidal activities of 5-substituted pyrazole oxime ether derivatives (새로운 pyrazole oxime ether 유도체의 살충활성 연구)

  • Park, No-Joong;Park, Hyun-Ja;Park, Min-Sup;Lee, Kee-In
    • The Korean Journal of Pesticide Science
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    • v.8 no.4
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    • pp.258-264
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    • 2004
  • The pyrazole family was discovered as effective insecticides/acaricides, and fenpyroximate and tebufenpyrad were introduced in the market. In this study, new series of pyrazole oxime ethers were designed and synthesized. The pyrazolone 1 was prepared by the condensation of ethyl acetoacetate with methylhydrazine, and then subsequently subjected to the Vilsmeier-Haack chloroformylation yielding 4-formyl-5-chloro-pyrazole 2. The nucleophilic aromatic substitution of 2 generally allowed the introduction of a wide range of heterocycles into the pyrazole ring. The resulting pyrazole aldehydes 3a-i were readily converted to the corresponding pyrazole oxime derivatives 4a-i, and subsequently to 5-substituted pyrazole oxime ether derivatives 6a-i. The screening assay results clearly show that the activities of 6d were comparable to those of fenpyroximate (6a) against BPH, DBM, and TSSM. It indicates that 6d has a potential to be developed as an insecticidal agent.

A Solid Phase Synthesis of Dihydro-1,4-dioxin and Dihydro-1,4-oxathiin Carboxanilides Using Polymer-bound Oxime Ester (고체상에 연결된 옥심 에스테르를 이용한 다이하이드로-1,4-다이옥신 및 다이하이드로-1,4-옥사티인 카르복스아닐라이드 유도체의 고체상 합성)

  • Hahn, Hoh-Gyu;Bae, Su-Yeal;Nam, Kee-Dal
    • The Korean Journal of Pesticide Science
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    • v.10 no.1
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    • pp.1-6
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    • 2006
  • A methodology for the syntheses of carboxanilides using solid support of 4-chloro-3-nitorbenzophenone oxime resin 5 was developed. Condensation of 4-chloro-3-nitorbenzophenone resin 6 with hydroxylamine hydrochloride salt gave oxime resin 5. The reaction of oxime resin 5 with dioxin and oxathiin derivatives 7a-d afforded the corresponding polymer-bound dioxin and oxathiin derivatives 9a-d. These polymer-bound resins 9a-d were treated respectively with aniline in the presence of acetic acid resulted in the corresponding dioxin carboxanilides 10a-d (yield, 5%-quantitative).

Controlled synthesis of reactive polymeric architectures for stimuli-responsive materials

  • Theato, Patrick;Nilles, Katja;Metz, Nadine
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.329-329
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    • 2006
  • Various new active ester monomers based on (meth)acrylates and 4-vinylbenzoic acid have been prepared. Investigation of the controlled radical polymerization behavior of the respective monomers resulted in excellent polymerization control, thus, opening synthetic routes to reactive block copolymers. Polymer analogous reactions with amines yielded functional polymers. In the case of the copolymer poly(N-isopropylacrylamide-co-acetone oxime acrylate) a lower critical solution temperature could be measured at $52^{\circ}C$. Thus, the reactive copolymer features two characters: reactive AND stimuliresponsive behavior.

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Selective Reduction with Zinc Borohydride. Reaction of Zinc Borohydride with Selected Organic Compounds Containing Representative Functional Groups (수소화붕소아연에 의한 선택환원. 수소화붕소아연의 대표적 유기화합물과의 반응)

  • Yoon Nung Min;Ho Jun Lee;Hye Kyu Kim;Jahyo Kang
    • Journal of the Korean Chemical Society
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    • v.20 no.1
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    • pp.59-72
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    • 1976
  • The addition of one mole of zinc chloride to 2.33 moles of sodium borohydride in tetrahydrofuran at room temperature gave a clear chloride-free supernatant solution of zinc borohydride after stirring three days and standing at room temperature.The approximate rates and stoichiometry of the reaction of zinc borohydride with 54 selected organic compounds were determined in order to test the utility of the reagent as a selective reducing agent. Aldehydes and ketones were reduced rapidly, aromatic ketones being somewhat slowly, and the double bond of cinnamaldehyde was not attacked. Acyl halides were reduced rapidly within one hour, but acid anhydrides were reduced at a moderate rate. Carboxylic acids, both aliphatic and aromatic, were slowly reduced to alcoholic stage. Esters were inert to this reagent but a cyclic ester, γ-butyrolactone, was slowly attacked. Primary amides were reduced slowly with partial evolution of hydrogen, whereas tertiary amides underwent neither reduction nor hydrogen evolution. Epoxides and nitriles were all inert, as well as nitro, azo, and azoxy compounds. Cyclohexanone oxime and phenyl isocyanate were reduced slowly but pyridine was inert. Disulfide, sulfoxide, sulfone and sulfonic acids were stable to this reagent.

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Determination of Processing Parameters Affecting the Conversion and Thermal Stability of Photocurable Acrylate-based Binder (아크릴계 광바인더의 전환율과 열안정성 향상을 위한 공정변수 결정)

  • Kim, Byungchul;Seo, Dong Hak;Chae, Heon-Seung;Shin, Seunghan
    • Applied Chemistry for Engineering
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    • v.23 no.1
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    • pp.18-22
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    • 2012
  • Photocurable binder for a transparent glass fiber composite was prepared with alicyclic methacrylate and fluorene-based diacrylate. ANOVA (analysis of variance) analysis was used to know main factors affecting the conversion of photocurable binder. It showed radiation intensity and photoinitiator (PI) concentration were main factors. The conversion of photocurable binder was simply increased with radiation intensity. Its increment however was abated with increasing PI concentration. We found that average conversion of the binder measured by FTIR-ATR was 87% when it was exposed to $5J/cm^2$ of UV dose with 5 wt% of PI. Oxime ester type PI was very effective to get a high degree of conversion, but it caused a yellowing problem. Owing to post-baking process, UV cured film showed an improved thermal stability by increase of conversion and removal of volatile organic compounds. TG% at $260^{\circ}C$ of film cured with 5 wt% of PI (TPO+MBF) and $5J/cm^2$ of UV radiation increased from 95.4 to 99.0% by post-baking at $230^{\circ}C$ for 5 min.