• 제목/요약/키워드: nitration

검색결과 128건 처리시간 0.023초

ADN(Ammonium Dinitramide)의 합성 (A Study on the Synthesis of Ammonium Dinitramide)

  • 정규현;심현호
    • 대한화학회지
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    • 제41권12호
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    • pp.661-665
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    • 1997
  • Ammonium dinitramide(ADN)은 최근에 개발된 고체 산화제로 ammonium perchlorate(AP)나 ammonium nitrate(AN) 등을 대체할 수 있다. Bis(2-cyanoethyl)amine에 니트로화 반응을 시킨 후 염기 처리하여 cyanoethyl기를 제거하고 NA2BF4를 사용하여 두번째 니트로 기를 도입하면 ADN 합성에 중요한 중간체인 3-N-Nitro-bis(2-cyanoethyl)amine은 N-nitroso 화합물의 산화반응으로 얻을 수도 있다.

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고낙차 펌프-터빈에서의 축계 진동 특성 (Characteristics of the Shaft Vibration in a High Head Pump-Turbine)

  • 하현천;최성필
    • 한국유체기계학회 논문집
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    • 제2권2호
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    • pp.27-31
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    • 1999
  • This paper describes the shaft vibration phenomena measured on a pump-turbine of a pumped storage power plant. The pump-turbine runs at a rotational speed of 450 rpm (7.5 Hz). The power output (load) of the pump-turbine is varied from 100 to 300 MW in the generating mode. The magnitude of the shaft vibration highly depends on the power load. The vibration magnitude of the shaft is very high in the middle load zone from 170 to 210 MW, elsewhere the vibration is low. From nitration spectra, it is shown that the frequency of major nitration in that load zone is 2.5 Hz which is approximately $34\%$ of the shaft rotating speed in Hz. This frequency component does not occur below and above that load zone. This subsynchronous vibration is caused by the flow induced disturbance due to spiral vortex flow downstream of the pump-turbine runner. Furthermore, the shaft vibration is highly decreased due to an increased bearing preload.

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Nitrosative protein tyrosine modifications: biochemistry and functional significance

  • Yeo, Woon-Seok;Lee, Soo-Jae;Lee, Jung-Rok;Kim, Kwang-Pyo
    • BMB Reports
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    • 제41권3호
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    • pp.194-203
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    • 2008
  • Nitrosative modifications regulate cellular signal transduction and pathogenesis of inflammatory responses and neuro-degenerative diseases. Protein tyrosine nitration is a biomarker of oxidative stress and also influences protein structure and function. Recent advances in mass spectrometry have made it possible to identify modified proteins and specific modified amino acid residues. For analysis of nitrated peptides with low yields or only a subset of peptides, affinity 'tags' can be bait for 'fishing out' target analytes from complex mixtures. These tagged peptides are then extracted to a solid phase, followed by mass analysis. In this review, we focus on protein tyrosine modifications caused by nitrosative stresses and proteomic methods for selective enrichment and identification of nitrosative protein modifications.

p-Dodecylbenzylidene-p'-hexyloxyaniline의 합성 (The Synthesis of p-Dodecylbenzylidene-p'-hexyloxyaniline)

  • 정노희;곽광수
    • 한국응용과학기술학회지
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    • 제20권3호
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    • pp.198-203
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    • 2003
  • In this study, we synthesized p-hexyloxybenzaldehyde(HBA) by using p-hydroxybenzaldehyde and n-hexylchloride. p-dodecylaniline(DDA) prepared by nitration and reduction of dodecylbenzene. The schiff base, p-dodecylbenzylidene-$p^\prime$-hexyloxyaniline (DBHA) was synthesized by reaction of HBA and DDA. The color of synthetic compound was pale-brown and the yield was 62%. All the synthetic compounds were identified by TLC, FT-IR and ${^{i}H}$-NMR.In this study, we synthesized p-hexyloxybenzaldehyde(HBA) by using p-hydroxybenzaldehyde and n-hexylchloride. p-dodecylaniline(DDA) prepared by nitration and reduction of dodecylbenzene. The schiff base, p-dodecylbenzylidene-p'-hexyloxyaniline(DBHA) was synthesized by reaction of HBA and DDA. The color of synthetic compound was pale-brown and the yield was 62%. All the synthetic compounds were identified by TLC, FT-IR and $^1H$-NMR.

4차 아민이 치환된 아닐린의 고리화반응 메카니즘 및 Pyrrolo[1,2-a]benzimidazoquinone 유도체의 합성에의 응용 (Mechanistic Studies for the Cyclization of t-Amine Substituted Anilines and Their Utilization to the Synthesis of Pyrrolo[1,2-a]benzimidazoquinone Derivatives)

  • 이창희;백호진;김국진;조규욱;오경택
    • 대한화학회지
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    • 제39권5호
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    • pp.408-413
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    • 1995
  • A few t-amine substituted anilines and amides were synthesized and cyclized to pyrrolo[1,2-a]benzimidazole by heating in various solvents having different polarity. Subsequent nitration of cyclized compound followed by reduction and oxidation of resulting amine afforded quinone such as 7 in 14% yield. The formation of imidazole moiety by thermal cyclization was independent on the solvent polarity. The regiochemistry for the nitration of 4 was unambiguously determined by chemical transformation.

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2-(p-메틸알릴아미노페닐)프로판산의 합성 (Facile Synthesis of 2-(p-Methylallylaminophenyl)propionic Acid (Alminoprofen))

  • 최홍대;윤호상;강병원;마정주;손병화
    • 약학회지
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    • 제36권1호
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    • pp.12-16
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    • 1992
  • A new method for the synthesis of alminoprofen, which is a non-steroidal antiinflammatory agent, was described. Ethyl 2-phenyl-propionate(4) was prepared by Friedel-Crafts reaction of benzene with ethyl ${\alpha}-chloro-{\alpha}(methylthio)acetate(1)$, followed by methylation and desulfurization of the resultant ethyl 2-(methylthio)phenylacetate(2). Ethyl 2-(p-aminophenyl)propionate(6) was obtained by nitration of (4) and successive reduction of ethyl 2-(p-nitrophenyl)propionate(5). Alminoprofen was synthesized by reaction of (6) with methallyl chloride, followed by hydrolysis of the resultant ethyl 2-(p-methylallylaminophenyl)propionate (7).

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Vitali 반응(反應)의 온도변화에 따른 영향 (Studien zur Entstehung organischer Nitroverbindungen unter abweichenden Bedingungen der Vitali-Reaktion)

  • 서명은
    • 생약학회지
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    • 제2호2호
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    • pp.83-86
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    • 1971
  • Tropane alkaloid 에 관한 Vitali 반응을 온도변화에 따라 실험한 결과 저온에서는 먼저 p 위치에서 nitro 화한 후 nitro 기의 강한 전자인력(電子引力)에 의하여 쉽게 ester의 가수분해가 진행하면서 산화당하여 p-nitrobenioic acid가 생성되었다. 그러나 고온인 $140^{\circ}$에서는 pyrolytic 에스텔분해가 먼저 일어난 후 nitro 화함으로서 2, 4-diritrobenzoic acid 와 3,5-dinitrobenzoic acid 가 생성되었다.

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