• Title/Summary/Keyword: Aromatic bromination

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A Green Protocol for the Bromination and Iodination of the Aromatic Compounds using H5IO6/NaBr and H5IO6/NaI in the Water

  • Yousefi-Seyf, Jaber;Tajeian, Kazem;Kolvari, Eskandar;Koukabi, Nadiya;Khazaei, Ardeshir;Zolfigol, Mohammad Ali
    • Bulletin of the Korean Chemical Society
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    • v.33 no.8
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    • pp.2619-2622
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    • 2012
  • Bromination and iodination of the aromatic compounds have efficiently been carried out at room temperature and $70^{\circ}C$, respectively, in short reaction times using orthoperiodic acid/sodium bromide (1:2) and orthoperiodic acid/sodium iodide (1:2) in water to prepare the corresponding halo compounds with excellent yields.

Functional Analyses and Application of Microbial Lactonohydrolases

  • Shimizu, Sakayu;Honda, Kohsuke;Kataoka, Michihiko
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.3
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    • pp.130-137
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    • 2002
  • Microbial lactonohydrolases (intramolecular ester bond-hydrolyzing enzymes) with unique properties were found. The lactonohydrolase from Fusarium oxysporum catalyzes enantiose-lective hydrolysis of aldonate lactones and D-pantoyl lactone (D-PL). This enzyme is useful for the large-scale optical resolution of racemic PL. The Agrobacterium tumefaciens enzyme catalyzes asymmetric hydrolysis of PL, but the stereospecificity is opposite to that of the Fusarium enzyme. Dihydrocoumarin hydrolase (DHase) from Acinetobacter calcoaceticus is a bifunctional enzyme, which catalyzes not only hydrolysis of aromatic lactones but also bromination of monochlorodi-medon in the presence of H$_2$O$_2$and dihydrocoumarin. DHase also hydrolyzes several linear esters, and is useful for enantioselective hydrolysis of methyl DL-$\beta$-acetylthioisobutyrate and regioselective hydrolysis of methyl cetraxate.

A Synthesis of New 2-Iminothiazolines and Their Antifungal Activities (II) (새로운 2-이미노티아졸린 유도체의 합성과 항균활성 (II))

  • Nam, Kee-Dal;Choi, Gyung-Ja;Cho, Kwang-Yun;Hahn, Hoh-Gyu
    • Applied Biological Chemistry
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    • v.41 no.6
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    • pp.471-476
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    • 1998
  • A synthesis and the screening of new 2-iminothiazolines (IV) of which structures are modified based on a lead compound, thiazoline for development of new agrochemical fungicide were described. Bromination of acetoacetanilides (I) which were prepared by the reaction of diketene with anilines gave the corresponding ${\gamma}-bromoacetoactanilide\;(II)$. Treatment of II with N-phenyl-N'-methyl thiourea (III) afforded IV, structure of which was confirmed by various spectroscopic methods. Antifungal activity of the new IV was tested against six kinds of typical plant diseases (in vivo). The IV with aromatic substituents showed remarkable activity against the Pyricuraria oryzae at 250 ppm in primary screening. The candidates with control value over 90% in primary screening were selected and further tested for second screening at lower concentrations. The IV which has an electron-withdrawing substituent such as halogen, especially fluorine in aryl group showed a higher activity as compared to those with electron-donating group and meta substituent was for optimal position.

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