• Title/Summary/Keyword: Halogen derivatives

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Highly Convenient and Large Scale Synthesis of 5-chloroindole and its 3-substituted Analogues (5-Chloroindole계 화합물의 Large Scale 합성)

  • Keetha, Laxminarayana;Palle, Sadanandam;Ramanatham, Vinodkumar;Khagga, Mukkanti;Chinnapillai, Rajendiran
    • Journal of the Korean Chemical Society
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    • v.55 no.2
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    • pp.240-242
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    • 2011
  • A large scale and commercially feasible synthesis of 5-chloroindole and its 3-substituted analogues has been described via a halogen - halogen exchange reaction from 5-bromoindole and its derivatives using cuprous chloride and dipolar aprotic solvent N-methyl-2-pyrrolidone in one pot with good yields.

Photocatalytic-Photooxidation of Halogen Derivatives of Phenols in Aqueous Solution (방향족 탄화수소 할로겐 유도체의 광촉매-광산화)

  • 김삼혁;권규혁;정오진
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.233-240
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    • 1999
  • Industrial waste which highly loaded by halogenide phenols was photooxidized by laboratory-scale photooxidation of these organic impurities in the presence of aerotropic and titaniumdioxide as photocatalyst. The disapperance of organic compounds was determined as a function of the irradiation time. Some contaminants such as 2-chlorophenol, 2-bromphenol, 3-bromphenol, 4-bromphenol, 2,4-dibromophenol and 2,6-dibromophenol were photodegraded separately to obtain information on the reaction rates, reactivities, and reaction mechanisms of the photooxidation, and on the stoichiometric correlation between organic reactant and inorganic products concentration in the course of the photocatalytic photoreaction.

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Synthesis and Fungicidal Activities of Substituted Phenyl Hydrazono-3-Methyl-1, 2-Isoxazol-5-One Derivatives. (치환 Phenyl Hydrazono-3-Methyl-1, 2-Isoxazol-5-One 유도체의 합성과 살균활성)

  • Park, Kwang-Wook;Keum, Young-Su;Park, Chang-Kyu
    • Korean Journal of Environmental Agriculture
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    • v.15 no.2
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    • pp.239-245
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    • 1996
  • Fungicidal activity has been examined for a series of substituted phenylhydrazono-3-methyl-1,2-isoxazol-5-one against plant pathogenic fungi. 3-methyl isoxazol-5-one was obtained from ethyl acetoacetate and hydroxyl amine. Final products were prepared by aromatic diazo coupling with 3-methyl isoxazol-5-one. Fungicidal activities against Rhizoctonia solani, Colletotrichum gloeosporioides, Cladosporium cucumerinum, Pythium ultimum were tested and Pythium ultimum were tested and Pythium ultimum was selected for quantitative measurement of activity. Methyl, halogen, nitro derivatives possessed high fungicidal activity at p-, o-, p- position, respectively. Methyl, halogen derivatives were much more active than alkoxy, nitro derivatives and the order of activity of halogen derivatives was F > Cl > I. This result implied that the activity was related to the molecular volume of substitutents.

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Antiinflammatory Evaluation and Synthesis of Benzothiazine Derivatives as Cyclooxygenase-2 Inhibitor (Cyclooxygenase-2 저해제로서의 benzothiazine 유도체 합성과 항염작용 평가)

  • 신혜순;박명숙;권순경
    • YAKHAK HOEJI
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    • v.44 no.3
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    • pp.272-278
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    • 2000
  • The antiinflammatory mechanism of NSAIDs is attributed to the reduction of prostaglandin synthesis by the direct inhibition of cyclooxygenase. Inhibition of prostaglandin production in organs such as stomach and kidney can result in gastric lesions, nephrotoxicity and increased bleeding. In this study, newly designed COX-2 inhibitors, synthesized 1,2-benzothiazine derivatives, were screened in vitro for selectivity of COX-1 and COX-2 inhibition properties. Lead compounds in the structure-activity relationship were studied to synthesize new highly selective COX-2 inhibitors.13 determine inhibitory effect of COX-2, synthesized 1,2-benzothiazine derivatives were screened with accumulation of prostaglandin by lipopolysaccharide (LPS) in aspirin-treated macrophages and murine macropharge cell. Some of synthesized 1,2-benzothiazine derivatives were shown to be effective as selective COX-2 inhibitory activity. Others exhibited a preferential inhibition of COX-2, although some COX-1 inhibitory activity was still present. As a conclusion, simple monomer derivatives were more active than dimer derivatives. Substitution of halogen (Br, C1) on the benzothiazine nucleus slightly enhanced inhibition activity.

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On the Development of Functional New Derivatives from Cellulose - Manufacturing of Reactive Cellulose Derivatives from Chlorinated Cellulose - (셀룰로오스로부터 기능성 신소재 개발에 관한 연구 - 염소화셀룰로오스로부터 반응성셀룰로오스의 제조 -)

  • Cho, Nam-Seok
    • Journal of the Korean Wood Science and Technology
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    • v.22 no.4
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    • pp.51-60
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    • 1994
  • Chlorodeoxycellulose derivatives have recently assumed importance since the halogen atoms can be changed with other functional groups to afford new derivatives of cellulose. Also, chlorinated cellulose has been employed as an intermediate in the preparation of various functional cellulose derivatives. In this study chlorodeoxycellulose was prepared by reaction of methylcellulose with mathanesulfonylchloride in N,N-dimethylformamide. Subsequently, conversion of the above chlorinated cellulose to unsaturated celluloseen was carried out by potassium tertiary butoxide in dimethyl sulfoxide. An anhydrocellulose as an intermediate for the reactive functional derivatives was made by simple alkali treatment. Preparation condition of allylated methylcellulose by using allylchloride and its thermal behavior were also described.

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Thermodynamic Study on the Solubilization of p-Halogenated Phenol Derivatives in TTAB Solution (TTAB 수용액에서 p-할로겐화 페놀유도체들의 가용화에 대한 열역학적 연구)

  • Lee, Byung-Hwan
    • Applied Chemistry for Engineering
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    • v.25 no.1
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    • pp.20-26
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    • 2014
  • The interaction of p-halogenated phenol derivatives with the micellar system of tetradecyltrimethylammonium bromide (TTAB) was studied by the UV/Vis spectrophotometric method. Effects of substituents, additives, and temperatures on the solubilization of phenol derivatives have been measured. The results show that all the values of ${\Delta}G^o$ and ${\Delta}H^o$ were negative and the values of ${\Delta}S^o$ were positive for all phenol derivatives within the measured temperature range. The calculated thermodynamic parameters depended on the size, the electro-negativity, and the hydrophobic property of halogen substituents. The addition of n-butanol results in the decrement in tthe Ks values and the addition of NaCl caused the increment in the Ks values for all the phenol derivatives. From these changes we can postulate that the solubilization sites of the phenol derivatives in the micelle depend severely on properties of the halogen-substituent.

Photodegradation of Halogen Derivatives of Aliphatic Hydrocarbon in Aqueous Photocatalytic Suspensions (지방족 탄화수소의 할로겐 유도체 수용액의 광촉매-광분해)

  • Jun, Jin;Jung, Hak-Jin;Kim, Hae-Jin;Kim, Sam-Hyeok
    • Journal of Environmental Science International
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    • v.6 no.1
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    • pp.75-88
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    • 1997
  • The rates of photodegradation, reactivities, and mechanisms of photooxidation for the aqueous solution containing with halogen derivatives of aliphatic hydrocarbons have been discussed with respect to the kinds of photocatalysts, concentration of photocatalytlc suspensions, strength of radiant power, time of illumination, changes of pH of substrate solution, wavelength of radiation, and pressure of oxygen gas saturated In the solution. These aqueous solutions suspended with 0.5 $gL^{-1}$ $TiO_2$ powder have been photodecomposed in the range of 100 and 93.8% per 1 hour if it is illuminated with wavelength (λ $\geq$ 300nm) produced from Xe-lamp(450W). The photocatalytic abilities have been increased In the order of $Fe_2O_3$ < CdS < $CeO_2$ < Y_2O_3$ <$TiO_2$, and rates of photodegradation for the solution have maldmum values in the condition of pH 6 ~ 8 and 3 psi-$O_2$ gL^{-1}$. These rates for the Photoolddation Per 1 hour were dependent on the size of molecular weight and chemical bonding for organic halogen compounds and the rates of photodegadation were increased in the order of $C_2H_5Br$ < CH_2Br_2$ < C_5H_11Cl C_2H_4Cl_2$ < tracts-$C_2H_2Cl_2$ < cis-C_2H_2Cl_2$ The T_{1/2}$ and t99% for these solutions were 5~21 and 40~90 minutes. respectively, and these values were coincided with Initial reaction kinetics(ro). It was found that reaction of photodegradation has the pseudo first-order kinetics controlled by the amount of $h^+_{VB}$ diffused from a surface of photocatalysts.

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Syntheses and Biological Activities of Uridine Nucleoside Derivatives (Uridine Nucleoside 유도체의 합성과 생물 활성)

  • Bong-Hun Lee;Jang-Su Park;Shin-Won Kang
    • Journal of Life Science
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    • v.9 no.1
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    • pp.63-68
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    • 1999
  • Many nucleoside compounds such as 5-halogen substituted uridine, 5'-amino-5'-deoxyuridine conjugates of amino acid, peptide, and penicillin G, 5'-monophosphate uridine derivatives and 5'-monophosphate uridine-fatty acid derivatives were chemically synthesized and their antifungal, antibacterial, and antitumor activities were tested. 5-Bromo-2',3'-O-isopropylideneuridine(6) inhibited the growth of Trichophyton rubrum at $0.2{\mu}$g/ml of MIC. 5'-Amino-5'-deoxyuridine-penicillin G(19), 5'-amino-5'-deoxyuridine-cyclo(Phe-Asp)(20), and 5-iodo-5'-amino-5'-deoxyuridine- penicillin G(22) had antibarterial activity(MIC was $6.25{\mu}$g/ml against S. aureus) and the latter two nucleoside compounds were the most antitumor derivatives(their $IC_{50}$ against L5178Y murine lymphoma cell was $6.5{\mu}$g/ml).

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