• Title/Summary/Keyword: intermediates

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Degradation of 4-Chlorophenol by a Photo-Fenton Process with Continuous Feeding of Hydrogen Peroxide (과산화수소 연속주입식 광펜톤산화공정에 의한 4-염화페놀 분해연구)

  • Kim, Il-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.1
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    • pp.31-38
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    • 2013
  • The degradation of 4-chlorophenol(4-CP) by various AOPs(Advanced Oxidation Processes) with continuous feeding of $H_2O_2$, including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been investigated. The photo-Fenton process showed the highest removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process and the combined UV process with continuous feeding of $H_2O_2$. In the photo-Fenton process, the optimal experimental condition for 4-CP degradation was obtained at pH 3. Also the 4-CP removal efficiency increased with decreasing of the initial 4-CP concentration. 4-chlorocatechol and 4-chlororesorcinol were identified as photo-Fenton reaction intermediates, and the degradation pathways of 4-CP in the aqueous phase during the photo-Fenton reaction were proposed.

Syntheses of Substituted tert.-Butyl(o-tolyl)-perpropionates (tert.-Butyl ${\beta}$-(o-tolyl)-perpropionate 치환체들의 합성)

  • Hahn, Chi-Sun;Martin, Michael M.
    • Journal of the Korean Chemical Society
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    • v.8 no.4
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    • pp.153-157
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    • 1964
  • The syntheses of substituted tert.-butyl ${\beta}$-(o-tolyl)- perpropionates via intermediates obtained by chloromethylation, malonic syntheses and decarboxylation is described. The intermediates substituted with a group possessing moderate substituent effect such as bromo, chloro, and methyl group were obtained in good yields. The nitro-substituted intermediat was obtained in poor yield. The chloromethylation of toluenes containing electron donating groups resulted in polymerization.

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Synthesis of 4-Phenyltetralone Derivatives and Reaction Mechanism

  • Kwon, Soon-Kyoung;Park, Young-Nam
    • Archives of Pharmacal Research
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    • v.23 no.4
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    • pp.329-331
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    • 2000
  • 4-(p-Chlorophenyl)tetralone (6) and 7-chloro-5-(p-chlorophenyl)tetralone (9) are key intermediates for the development of benzazepinone derivative haftens. These compounds could be synthesized from 4-phenyltetralone derivatives by triflic acid catalyzed Friedel-Crafts reaction. The reaction mechanism of Friedel-Crafts alkylation/acylation with lactones in triflic acid is presented. According to our tentative research, ring opening of protonated lactone (2) occurs in alkyl cleavage and the rate of the reaction is not dependent on concentration of triflic acid. So, alkylation of lactone in Friedel-Crafts reaction is presumed to be $A_{AL}$ 1. In second step, intramolecular acylation of the intermediates 4 to 6, 4 can be transformed to a triflic acid-carboxylic anhydride and then the cyclization is undergone after leaving of the triflate anion.

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Ring Opening of Pyrolidine and Formation of N-Protected Amino Ketones; Synthesis of 5-Amino-2-pentanone Derivatives (피롤리딘의 개환과 N-프로텍티드 아미노 케톤의 형성; 5-아미노-2-펜타논 유도체의 합성)

  • Park, Myung-Sook
    • YAKHAK HOEJI
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    • v.40 no.3
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    • pp.300-305
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    • 1996
  • The base-induced elimination of N-protected 2-(bromomethyl)pyrrolidines 12a-c with KHMDS in THF at -78$^{\circ}C$ for 1h gave exocyclic enamines 13a-c. The acidic catalyzed pr otonation on ${\beta}$-carbon atom of 2-(methylene)pyrrolidines 13a-c with $H_3PO_4$ formed endocyclic N-iminium intermediates 14(or 15). Nucleophilic attack of alpha-carbon atom and hydrolysis of N-iminium ion gave carbocationic adduct (aminoalcohol) 16 from which 5-amino-2-pentanones 17a-c were formed after deprotonation.

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The effects of Seungmagalgeuntang-gamibang on the anti-allergic and immune response to mice (升麻葛根湯加味方이 마우스의 抗 ALLERGY 및 免疫反應에 미치는 影響)

  • Kim, Nam-Kwen;Hwang, Chung-Yeon;Lim, Gyu-Sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.8 no.1
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    • pp.1-19
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    • 1995
  • Seungmagalgeuntang-gamibang has long been known to have anti-allergic effect. However, the mechanism of action of Seungmagalgeuntang-gamibang is not well investigated. The author analysed the effects of Seungmagalgeuntang-gamibang on the vascular permeability, delayed-type and contact hypersensitivities, and phagocytic function, the results obtained are as follows: 1. Administration of Seungmagalgeungtang-gamibang decreased the vascular permeability induced by serotonin in the mouse. 2. Administration of Seungmagalgeuntang-gamibang decreased the vascular permeability induced by histamine without statistical significant. 3. Administration of Seungmagalgeuntang-gamibang decreased the delayed-type hypersensitivity induced by sheep red blood cells. 4. Administration of Seungmagalgeungtang-gamibang decreased the contact hypersensitivity induced by dinitrochlorobenzene. 5. Seungmagalgeungtang-gamibang increased the phagocytic-activities of macrophages in vitro and in vivo. 6. Seungmagalgeungtang-gamibang enhanced the formation of reactive oxygen intermediates in vitro and in vivo. The above results demonstrate that Seungmagalgeuntang-gamibang suppresses the hypersensitivity reactions with increasing the phagocytic functions and formations of reactive oxygen intermediates from macrophages.

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Continuous Cell-Free Protein Synthesis Using Glycolytic Intermediates as Energy Sources

  • Kim, Ho-Cheol;Kim, Tae-Wan;Park, Chang-Gil;Oh, In-Seok;Park, Kyung-Moon;Kim, Dong-Myung
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.885-888
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    • 2008
  • In this work, we demonstrate that glycolytic intermediates can serve as efficient energy sources to regenerate ATP during continuous-exchange cell-free (CECF) protein synthesis reactions. Through the use of an optimal energy source, approximately 10 mg/ml of protein was generated from a CECF protein synthesis reaction at greatly reduced reagent costs. Compared with the conventional reactions utilizing phosphoenol pyruvate as an energy source, the described method yields 10-fold higher productivity per unit reagent cost, making the techniques of CECF protein synthesis a more realistic alternative for rapid protein production.

Degradation of 2,3-dichlorophenol by a Photo-Fenton Process with Continuous Pump-Feeding of Hydrogen Peroxide (동력펌프주입식 광펜톤시스템에 의한 2,3-디염화페놀 분해특성 연구)

  • Kim, Il-Kyu
    • Journal of Power System Engineering
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    • v.18 no.6
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    • pp.84-90
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    • 2014
  • The degradation of 2,3-dichlorophenol(2,3-diCP) by various advanced oxidation systems with continuous feeding of hydrogen peroxide including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been conducted. The highest removal efficiency for 2,3-diCP in the aqueous phase was obtained by the photo-Fenton process among the advanced oxidation systems. In the photo-Fenton process, The removal efficiency of 2,3-diCP decreased with increasing pH in the range of 3 to 6, and it decreased with increasing initial concentration. As the intermediates of 2,3-diCP by photo-fenton reaction, 3,4-chlorocatechol and 2,3-dichlorohydroquinone were detected, thus the degradation pathways were proposed.

Biodegradation of Phenanthrene by Sphingomonsa sp. Strain KH3-2

  • Shin, Su-Kyuong;Oh, Young-Sook;Kim, Sang-Jin
    • Journal of Microbiology
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    • v.37 no.4
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    • pp.185-192
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    • 1999
  • A phenanthrene-degrading bacterium was isolated from an oil-spilled intertidal sediment sample and identified as Sphingomonas sp. KH3-2. The strain degraded polycyclic aromatic compounds such naphthalene, fluorene, biphenyl, and dibenzothiophene. When strain KH3-2 was cultured for 28 days at 25C, a total of 500 ppm of phenanthrene was degrated with a concomitant production of biomass and Folin-Ciocalteau reactive aromatic intermediates. Analysis of intermediates during phenanthrene degradation using high-performance liquid chromatography and gas chromatography/mass spectrometry indicated that Sphingomonas sp. KH3-2 primarily degrades phenanthrene to 1-hydroxy-2-naphthoic acid (1H2NA) and further metabolizes 1H2NA through the degradation pathway of naphthalene.

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1,2,4-Triazole Fused Heterocycles; Part 3. Preparation of 1-(1-Phenylethenyl)-5-(N-substituted amino)-1,2,4-triazoles and 4H-1,2,4-Triazolo[1,5-c][1,3,5]oxadiazines

  • 이기정;이유석;송동혁
    • Bulletin of the Korean Chemical Society
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    • v.16 no.11
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    • pp.1037-1042
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    • 1995
  • The reaction of acetophenone 1-ureidoethylidenehydrazones 6 with a mixture of triphenylphosphine, carbon tetrachloride, and triethylamine in dichloromethane provides a general route to 1-(1-phenylethenyl)-5-(N-substituted amino)-1,2,4-triazoles 11 via the electrocyclization of the expected azino carbodiimide intermediates 9 to give the resonance stabilized azomethine imine 10a followed by a proton abstraction from the methyl group by amide anion. However, the same reaction of benzaldehyde 1-ureidoethylidenehydrazones 5 was unsuccessful. Under the same conditions, the reactions of benzaldehyde 1-N-acylureidoethylidenehydrazones 7 or acetophenone 1-N-acylureidoethylidenehydrazones 8 afforded 4H-1,2,4-triazolo[1,5-c][1,3,5]oxadiazines 16 or 17 via the zwitterionic species 15, or a [4+2] intramolecular cycloaddition from the carbodiimide intermediates 14, respectively.

Interaction of Hydrosilanes with the Surface of Rhodium

  • Boo Bong Hyun;Hong Seung Ki;Lee Sun Sook;Kim Hyun Sook
    • Bulletin of the Korean Chemical Society
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    • v.15 no.12
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    • pp.1103-1107
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    • 1994
  • Interaction of triethylsilane and diphenylsilane ($Ph_2$$SiH_2$, $Ph_2$$SiD_2$) with the surfaces of rhodium has been examined by trapping the reaction intermediates with 2,3-dimethyl-l,3-butadiene. 1,4-Hydrosilylation of the diene is predominantly observed to occur under mild condition over the rhodium catalyst. It is inferred from the product analyses that silylene and silyl radicals bonded to rhodium surfaces are the intermediates for addition of silylene to the diene, and for 1,4-hydrosilylation, respectively.