• Title, Summary, Keyword: chlorides

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Carbonylation of Benzal Chlorides to Alkyl Phenylacetates using $Fe(CO)_5$

  • Shim, Sang-Chul;Doh, Chil-Hoon;Lee, Sung-Yub;Cho, Chan-Sik
    • Bulletin of the Korean Chemical Society
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    • v.11 no.5
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    • pp.420-422
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    • 1990
  • Various substituted benzal chlorides are converted into alkyl phenylacetates ($ArCH_2COOR$) under CO atmosphere on reaction with a catalytic amount of Fe(CO)$_5$, a base, and an alcohol. The optimum conditions are found as atmospheric pressure of CO, 40$^{\circ}C$, potassium hydroxide as base, and medium of alcohol.

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Application of Cl3CCONH2/PPh3 towards the Synthesis of Bioactive Amides

  • Chaysripongkul, Skydow;Pluempanupat, Wanchai;Jang, Doo-Ok;Chavasiri, Warinthorn
    • Bulletin of the Korean Chemical Society
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    • v.30 no.9
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    • pp.2066-2070
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    • 2009
  • $Cl_3CCONH_2$ coupled with $PPh_3$ was determined to be an effective reagent for the conversion of carboxylic acids to their corresponding acid chlorides. Subsequently, these acid chlorides were successfully trapped with amines in the presence of 4-picoline, yielding amides. This practical and efficient protocol can be utilized for the synthesis of biological amides in excellent yields.

Kinetic Studies on Solvolyses of Substituted Cinnamoyl Chlorides in Alcohol-Water Mixture (알코올-물 혼합 용매계에서 치환된 염화신남오일의 가용매분해반응에 관한 속도론적 연구)

  • Koo, In Sun;Kim, Jung Soon;An, Sun Kyoung;Yang, Kyu Il;Lee, Ic Hoon
    • Journal of the Korean Chemical Society
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    • v.43 no.5
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    • pp.527-534
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    • 1999
  • Solvolyses of para-substituted cinnamoyl chlorides in aqueous binary mixtures of acetone, ethanol, methanol were investigated at 25.0$^{\circ}C$. These data were interpreted using the Grunwald-Winstein relationship, Hammett equation, and quantum mechanical model. Grunwald-Winstein plots of the first-order rate constants for para-substituted cinnamoyl chlorides with $Y_{CI}$ showed marked dispersions into three separate curves for the three aqueous mixtures with a large m vaIue for aqueous alcohol solvents. This study has shown that the potential energy surface and quanturm mechanical model predict transition state variation correctly for $S_N1$ like $S_N2$ reaction mechanism of para-substituted cinnamoyl chlorides.

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Seasonal properties of airborne chlorides to the result of 3 year-measurement (3년간의 측정결과에 따른 비래염분의 계절별 특성)

  • Lee, Jong-Suk;Ahn, Ki-Hong;Kim, Do-Gyeum;Lee, Jang-Hwa
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.573-576
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    • 2008
  • When the concrete structures are in contact with seawater, concentration of chloride for estimating chloride diffusion coefficient can be defined as the chloride concentration of sea water. However, in case the concrete structures, constructed in the seashore, aren't directly in contact with seawater, it is difficult to establish the interface concentration of chloride. In addition, marine concrete structures are greatly affected by salt attack such as rebar corrosion, among the cause of salt attack, airborne chlorides is primary factor. Therefore, in this study, salt attack environment by airborne chlorides was investigated in terms of a seasonal distribution at 72 spots, 27 areas in the East, West, South coast for 3 years from July '03 to June '06. Results indicated that in the East and South coast, the amount of the airborne chlorides is comparatively higher in summer, in the West coast, higher in winter according to the seasonal wind.

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Synthesis of Quinoxaline Derivatives from Benzofuroxan (Part I) (Benzofuroxan으로부터 Quinoxaline 유도체의 합성(제1보))

  • Kim, Ho-Sik;Hur, Jae-Hyuck
    • Journal of the Korean Chemical Society
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    • v.48 no.4
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    • pp.385-393
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    • 2004
  • 2-Ethoxycarbonyl-3-methylquinoxaline 1,4-dioxide (8) was synthesized from benzofuroxan and ethyl acetoacetate. The reaction of compound 8 with hydrazine hydrate or selenium dioxide gave 2-hydrazinocarbonyl-3-methylquinoxaline 1,4-dioxide (9) or 2-ethoxycarbonyl-3-formylquinoxaline 1,4-dioxide (10), respectively. The reaction of compound 9 with alkanoyl chlorides, benzoyl chlorides, heteroacyl chlorides, and benzenesulfonyl chlorides afforded 3-methyl-2-(substituted hydrazinocarbonyl)quinoxaline 1,4-dioxides (11-14), respectively. The reaction of compound 9 with sodium azide gave 2-azidocarbonyl-3-methylquinoxaline 1,4-dioxide (15), and then its refluxing in dioxane/alcohols resulted in the Curtius rearrangement to give N-(3-methyl-1,4-dioxoquinoxalin-2-yl)-alkyl carbamates (16). The reaction of compound 15 with substituted anilines afforded 2-(3-substituted phenylureido)-3-methylquinoxaline 1,4-dioxides (17). The reaction of compound 10 with benzoic hydrazide or substituted anilines provided quinoxaline 1,4-di-oxides (18, 19), respectively. The herbicidal and fungicidal activities of the synthesized compounds were investigated.

Overexpression of afsR and Optimization of Metal Chloride to Improve Lomofungin Production in Streptomyces lomondensis S015

  • Wang, Wei;Wang, Huasheng;Hu, Hongbo;Peng, Huasong;Zhang, Xuehong
    • Journal of Microbiology and Biotechnology
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    • v.25 no.5
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    • pp.672-680
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    • 2015
  • As a global regulatory gene in Streptomyces, afsR can activate the biosynthesis of many secondary metabolites. The effect of afsR on the biosynthesis of a phenazine metabolite, lomofungin, was studied in Streptomyces lomondensis S015. There was a 2.5-fold increase of lomofungin production in the afsR-overexpressing strain of S. lomondensis S015 N1 compared with the wild-type strain. Meanwhile, the transcription levels of afsR and two important genes involved in the biosynthesis of lomofungin (i.e., phzC and phzE) were significantly upregulated in S. lomondensis S015 N1. The optimization of metal chlorides was investigated to further increase the production of lomofungin in the afsR-overexpressing strain. The addition of different metal chlorides to S. lomondensis S015 N1 cultivations showed that CaCl2, FeCl2, and MnCl2 led to an increase in lomofungin biosynthesis. The optimum concentrations of these metal chlorides were obtained using response surface methodology. CaCl2 (0.04 mM), FeCl2 (0.33 mM), and MnCl2 (0.38 mM) gave a maximum lomofungin production titer of 318.0 ± 10.7 mg/l, which was a 4.1-fold increase compared with that of S. lomondensis S015 N1 without the addition of a metal chloride. This work demonstrates that the biosynthesis of phenazine metabolites can be induced by afsR. The results also indicate that metal chlorides addition might be a simple and useful strategy for improving the production of other phenazine metabolites in Streptomyces.

Nucleophilic Displacement at Sulfur Center (VIII). Solvolysis of 1-and 2-Naphthalene Sulfonyl Chlorides in Ethanol-Water Mixture (황의 친핵성 치환반응 (제8보). 물-에탄올 혼합용매 속에서 1-및 2-염화나프탈렌 술포닐의 가용매 분해반응)

  • Uhm, Tae Seop;Lee, Ik Choon;Kim, Jae Rok
    • Journal of the Korean Chemical Society
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    • v.20 no.5
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    • pp.358-363
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    • 1976
  • Kinetic studies on solvolytic reactions of 1-and 2-naphthalene sulfonyl chlorides in ethanol-water mixtures have been carried out by means of conductometry at several temperatures. The rate constant for 2-naphthyl compound was larger than that for 1-naphthyl compound. This was contrary to the prediction of MO theory and could be rationalized as due to the peri-hydrogen effect in the transition state for 1-naphthyl compound. Based on m values of Winstein plots and n values of Kivinen pacolots it was concluded that the solvolytic displacement of the two naphthalene sulfonyl chlorides in ethanol-water mixtures proceed via $S_N2$ process.

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Nucleophilic Substitution at a Carbonyl Carbon Atom (X). Nucleophilic Substitution Reactions of N,N-Disubstituted Carbamoyl Chlorides (카르보닐탄소원자의 친핵성 치환반응 (제10보). N,N-이치환 염화카르바모일의 친핵성 치환반응)

  • Shi Choon Kim;Ho Bong Song;Ikchoon Lee
    • Journal of the Korean Chemical Society
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    • v.23 no.6
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    • pp.368-373
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    • 1979
  • Kinetic studies have been carried out on solvolyses and halide exchanges $(Cl^-,\;Br^-,\;I^-)$ of N,N-dimethyl-, N,N-diethylcarbamoyl chlorides, and solvolyses of N,N-diphenylcarbamoyl chloride. Kinetic results together with simple MO analysis indicated that: (a) N,N-dialkylcarbamoyl chlorides reacted via the $S_N2$ mechanism, while N,N-diphenylcarbamoylchloride reacted via the $S_N1$ mechanism; (b) in chloride exchanges, the bond-breaking appeared to be important, whereas in bromide and iodide exchanges, the bond-formation was shown to be important.

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Hydration and mechanical properties of Blended Cement added Bypass dust (By-pass Dust를 첨가한 혼합 시멘트의 수화 및 기계적 특성)

  • 성진욱;나종윤;김창은;이승헌;이봉한;김수룡;류한웅
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.33-39
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    • 1999
  • This study was conducted to confirm the effect of bypass dust on the hydration and mechanical properties of the cement pastes and mortar obtained from ordinary Portland cement (OPC), OPC-slag and OPC-fly ash system. The rate of heat evolution is accelerated with the content of By-pass Dust(BD). total heat evolution increased because alkali-chlorides activated the hydration of blended cement. Compressive strength and bound water content show maximum value at 5wt% By-pass Dust(BD) on each curing time in ordinary Portland cement and slag blended cement. Ca(OH)2 content of Ordinary Portland Cement increased as the content of BD and curing time. In blended cement, the formation of Ca(OH)2 is active at early hydration stage. By pozzolanic reaction, the content of Ca(OH)2 is decreased as curing time goes by. According to the BD content stable chlorides complex of Friedel's salt (C3A·CaCl2·10H2O) is created. Due to the hydration activation effect of chlorides and alkali we observed Type II C-S-H, which developed into densest microstructure.

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Inactivation Study of Pyridine-Linked Dehydrogenases by $N^1$-Alkylnicotinamide Chlorides ($N^1$-Alkylnicotinamide Chloride 유도체에 의한 탈수소 효소의 불활성화에 관한 연구)

  • Kim Soo-Ja;Lee Hyun Jae
    • Journal of the Korean Chemical Society
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    • v.20 no.5
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    • pp.406-416
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    • 1976
  • A series of $N^1$-alkylnicotinamide chlorides, $N^1$-methyl-to $N^1$-dodecylnicotinamides inclusive were studied with rabbit muscle L-${\alpha}$-glycerophosphate dehydrogenase to investigate the possibility of reversible and irreversible inactivation of the pyridine-linked dehydrogenases by the coenzyme-competitive inhibitor derivatives. The inhibition of the enzyme by $N^1$-alkylnicotinamide chlorides was demonstrated to be reversible at the dilute concentration of the inhibitors but this reversible inhibition was found to be followed by an irreversible time-dependent inactivation measuable at high concentrations of the inhibitors. The properties of this time-dependent inactivation were discussed on the basis of the denaturation of the enzyme by the binding of small micelle-like structures formed at higher concentrations of the inhibitors.

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