• Title/Summary/Keyword: nitration

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

  • Chung, Kyoo Hyun;Sim, Hyun Ho
    • Journal of the Korean Chemical Society
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    • v.41 no.12
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    • pp.661-665
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    • 1997
  • Recently ADN was disclosed to replace AP or AN as a solid oxidizer. 3-N,N-Dinitraminopropanitrile, a key intermediate in the preparation of ADN, was synthesized from bis(2-cyanoethyl)amine by the sequence: nitration of bis(2-cyanoethyl)amine followed by decyanoethylation by base and the second nitration with NO2BF4. 3-N-Nitro-bis(2-cyanoethyl)amine could also be obtained by the oxidation of the corresponding N-nitroso compound.

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

  • Ha, Hyun-Cheon;Choi, Seong-Pil
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.2 s.3
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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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    • v.41 no.3
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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.

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

  • Jeong, Noh-Hee;Kwack, Kwang-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.3
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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.

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

  • Lee, Chang-Hee;Baik, Ho-Jin;Kim, Kuk-Jin;Cho, Kiu-Uk;Oh, Kyung Taek
    • Journal of the Korean Chemical Society
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    • v.39 no.5
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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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Facile Synthesis of 2-(p-Methylallylaminophenyl)propionic Acid (Alminoprofen) (2-(p-메틸알릴아미노페닐)프로판산의 합성)

  • Choi, Hong-Dae;Yun, Ho-Sang;Kang, Byung-Won;Ma, Jung-Joo;Son, Byeng-Wha
    • YAKHAK HOEJI
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    • v.36 no.1
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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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Studien zur Entstehung organischer Nitroverbindungen unter abweichenden Bedingungen der Vitali-Reaktion (Vitali 반응(反應)의 온도변화에 따른 영향)

  • Su, Myung-Eun
    • Korean Journal of Pharmacognosy
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    • v.2 no.2
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    • pp.83-86
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    • 1971
  • The effects of temperature on Vitali test for tropane alkaloids were investigated. At low temperatures, after nitration occurred at para-position, the electron force of the nitro group caused hydrolysis of ester and oxidation, p-nitrobenzoic acid being produced. At $140^{\circ}C(high{\;}temperature)$, pyrolytic deesterification first took place and then nitration followed, yielding 2,4-dinitrobenzoic and 3,5-dinitrobenzoic acids.

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