• Title/Summary/Keyword: Isosterism

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Design of new 1,3-thiazoline derivatives by isosterism and antifungal activity of new 2,4-diimino-1,3-thiazolidines (Isosterism을 이용한 새로운 1,3-thiazoline 유도체의 디자인 및 신규 2,4-diimino-1,3-thiazolidine 유도체의 살균 활성)

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Lim, Chul-Soo;Mah, He-Duck;Kim, Jin-Cheol;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.7 no.1
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    • pp.51-57
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    • 2003
  • For the purpose of a development of new agrochemical fungicides, new compound 4 in which 1,3-thiazoline scaffold as well as urea moiety in the structure was designed through molecular modification of lead compound, 2-imino-1,3-thiazone based on isosterism. The reaction of N-alkylthiourea 5 and bromoacetonitrile in ethanol gave 2,4-diimino-1,3-thiazolidine hydrobromide 6 regioselectively, which was treated with isocyanates gave the corresponding 8 which is tautomer of 4. Antifungal screening (in vivo) of the synthesized compound 8 against typical plant diseases, which include rice blast, rice sheath blight, cucumber gray mold, tomato late blight, wheat leaf rust, and barley powdery mildew, was carried out. Antifungal activities against rice blast of the compound 8 were weaker than those of 2-phenylimino-1,3-thiazoline 1. Some compounds showed weak antifungal activities against wheat leaf rust.

Synthesis of New 2,4-Diimino-1,3-thiazoles and the Structure Determination (새로운 2,4-Diimino-1,3-thiazoles 유도체의 합성과 구조 결정)

  • Hoh-Gyu Hahn;Chul-soo Lim;Heduck Mah
    • Journal of the Korean Chemical Society
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    • v.47 no.1
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    • pp.38-42
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    • 2003
  • For the purpose of developing new agrochemical fungicides, compound 2 possessing 1,3-thiazole scaffold as well as urea moiety in the structure was designed through molecular modification of lead compound, 2-imino-1,3-thiazoline based on isosterism. The reaction of N-methylthiouea 5 and bromoacetonitrile in ethanol gave 2,4-diimino-1,3-thiazole 4 regioselectively, which was treated with phenyl isocyanates to give the corresponding 7 which is tautomer of 2. The structural assignment of 7 was confirmed by various spectra($^1H$ NMR, $^{13}C$ NMR, FT-IR, HRMS), and X-ray crystallographic data. Compound 8 which is a structural isomer of 7 was formed through thermodynamically unstable intermediate 2,4-diimino-1,3-thiazole 6.