• Title/Summary/Keyword: Thiazoline

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Conversion of Penicillin to Cephalosporin. The Iodination of Thiazoline-azetidinone in the Presence of Water (페니실린에서 세파로스포린으로의 전환. 물 존재하에서 티아졸린-아제티디논의 요오드화 반응)

  • Choe, In Yeong;Jeong, Gyu Hyeon;Lee, Yun Yeong;Gu, Yang Mo
    • Journal of the Korean Chemical Society
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    • v.34 no.1
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    • pp.102-107
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    • 1990
  • The reaction of thiazoline-azetidinone (7) with $I_2$ in $CH_2Cl_2-H_2O$ gave directly 3-iodo-3-methylcepham (4). A phase transfer catalyst considerably increased the reaction rate. Similar to the hydrolysis of thiazoline-azetidinone (7) under a weak acidic condition, thiazole (10) was given as major product in the treatment with 0.1 eq. of iodine. The difference between cyclization reaction and hydrolysis could be explained in terms of solvents, the amount of iodine and the nature of thiazoline-azetidinones (7).

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Synthesis of 2-Cyanoimino-1,3-thiazoline (2-Cyanoimino-1,3-thiazoline 유도체의 합성)

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Park, Ik-Kyu;Mah, He-Duck
    • The Korean Journal of Pesticide Science
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    • v.7 no.2
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    • pp.155-158
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    • 2003
  • 2-Imino-1,3-thiazolines 1 show selective antifungal activity against pyricularia oryzae by new mode of action. A synthesis of novel 2-cyano-l,3-thiazolines 2 in which cyano moiety is substituted in imino group at C-2 of 1 is described. The lone pair electrons of sulfur and nitrogen as well as strong electron withdrawing cyano substituent in 1,3-thiazoline scaffold would effect the biological activity of 2-imino-1,3-thiazoline series. Regiospecific nucleophilic attack of thiourea 4 for $\gamma$-chloro-$\beta$-ketoacetoacetanilide 3 followed by acid catalyzed dehydration gave 2.

Synthesis of 2-phenylimino-1,3-thiazoline hydrochloride salts (2-Phenylimino-1,3-thiazoline 염산염 유도체의 합성)

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Shin, Sun-Ho;Mah, He-Duck
    • The Korean Journal of Pesticide Science
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    • v.5 no.2
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    • pp.13-17
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    • 2001
  • A synthesis of new 2-phenylimino-1,3-thiazolines 2 for the purpose of development of new agrochemical fuugicide was described. Reaction of chlorine with diketene followed by treatment of benzylamine without isolation of intermediate 8a gave ${\gamma}-chloro-{\beta}-keto$ benzylamide 10a. Thioureas 4 obtained from the reaction of methyl isothiocyanate with aniline derivatives were subjected to 10a in acetone solution to afford the corresponding 2-phenylimino-1,3-thiazoline hydrochloric acid salts 2 through unisolable inltermediates 11 and 12. The plausible reaction mechanism including nucleophilic attack of sulfur assisted neighboring nitrogen lone pair electron on phenyl of thiourea 4 was discussed.

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Neuroprotective effects of the antioxidant action of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride against ischemic neuronal damage in the brain

  • Ha, Seung Cheol;Han, A Reum;Kim, Dae Won;Kim, Eun-A;Kim, Duk-Soo;Choi, Soo Young;Cho, Sung-Woo
    • BMB Reports
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    • v.46 no.7
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    • pp.370-375
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    • 2013
  • Ischemia is characterized by oxidative stress and changes in the antioxidant defense system. Our recent in vitro study showed that 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride protects cortical astrocytes against oxidative stress. In the current study, we examined the effects of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride on ischemia-induced neuronal damage in a gerbil ischemia/reperfusion models. Extensive neuronal death in the hippocampal CA1 area was observed 4 days after ischemia/reperfusion. Intraperitoneal injection of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride (0.3 mg/kg body weight) significantly prevented neuronal death in the CA1 region of the hippocampus in response to transient forebrain ischemia. 2-Cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride administration reduced ischemia-induced increases in reactive oxygen species levels and malondialdehyde content. It also attenuated the associated reductions in glutathione level and superoxide dismutase, catalase, and glutathione peroxidase activities. Taken together, our results suggest that 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride protects against ischemia-induced neuronal damage by reducing oxidative stress through its antioxidant actions.

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.

The Evidence of Tautomerization of 2-thiazoline-2-thiol on Ge (100) Surface

  • Park, Yeong-Chan;Yang, Se-Na;Kim, Ye-Won;Im, Hui-Seon;Kim, Se-Hun;Lee, Han-Gil
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.213-213
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    • 2012
  • We first confirm the tautomerization of 2-thiazoline-2-thiol on Ge (100) surface using CLPES and DFT calculation. We clearly confirmed that there exist two different molecular structures (we well show in our poster) in C 1s, N 1s, and S 2p CLPES spectra. Moreover, we obtained two plausible adsorption structures using DFT calculation which are that one is s-dative bonded structure and the other is SH dissociated-N-dative bonded structure although their stabilities are different on Ge (100) surface. We will investigate this interesting result for the confirmation of tautomerization of 2-thiazoline-2-thiol molecule adsorbed on Ge (100) surface.

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Excavation of 3-amino-2-benzylimino-1,3-thiazolines, Selective Fungicide against Phytophthora infestans and Magnaporthe grisea (토마토 역병균과 벼 도열병균에 선택적인 살균활성의 3-아미노-2-벤질이미노-1,3-티아졸린 유도체 발굴)

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Shin, Dong-Yoon;Choi, Gyung-Ja;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.10 no.3
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    • pp.165-171
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    • 2006
  • A new 3-amino-1,3-thiazoline chemical library was synthesized through parallel synthetic technology and in vivo antifungal activity of the compounds were investigated against the typical 6 plant diseases (100 ppm). The characteristic feature of these derivatives was that both a benzyl moiety in C-2 imino and an amino group in C-3 of 2-imino-1,3-thiazoline scaffold were substituted in the molecule respectively. Some compounds showed antifungal activity with selectivity against tomato late blight and rice blast. The fungitoxicity would be attributed to 3,4-dichlorophenyl moiety of the benzyl group.

Lead optimization of 2-imino-1,3-thiazolines and in vivo antifungal activity against rice blast (I) (2-이미노-1,3-티아졸린 유도체의 최적화 및 벼 도열병에 대한 방제활성 (I))

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Bae, Su-Yeal;Park, Ik-Kyu
    • The Korean Journal of Pesticide Science
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    • v.8 no.3
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    • pp.168-174
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    • 2004
  • In a course of the process for a lead optimization of 2-imino-l,3-thiazolines 1 which show a selective in vivo antifungal activity against rice blast, new compounds 2 in which C-5 was substituted by methyl group of the lead compound were synthesized and tested for the biological activity. Bromination of $\beta$-keto ester 7 followed by the reaction with thiourea and hydrolysis gave 2-imino-5-methyl-l,3-thiazoline carboxylic acid 3. Coupling reactions of 3 with aniline derivatives afforded 17 kinds of the corresponding 2-imino-5-methyl-l,3-thiazoline carboxanilides 2. Their in vivo antifungal activity against rice blast was weaker than that of 1, indicating that the in vivo antifungal activity of 2-imino-l,3-thiazolines was affected by the substituent at C-5. These results would be an important data for the molecular design in the lead optimization process of this series.

Study of Thiazoline Derivatives for the Design of Optimal Fungicidal Compounds Using Multiple Linear Regression (MLR)

  • Han, Won-Seok;Lee, Jin-Kak;Lee, Jun-Seok;Hahn, Hoh-Gyu;Yoon, Chang-No
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1703-1706
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    • 2012
  • Rice blast is the most serious disease of rice due to its harmfulness and its world wide distribution. $Magnaporthe$ $grisea$ is the cause of rice blast disease and destroys rice enough to feed several tens of millions of people each year. Fungicides are commonly used to control rice blast. But $M.$ $grisea$ acquires resistance to chemical treatments by genetic mutations. 2-Phenylimino-1,3-thiazolines were proposed as a novel class of fungicides against $M.$ $grisea$ in the previous study. To develop compounds with a higher biological activity, a new series of 2-phenylimino-1,3-thiazolines was synthesized and its fungicidal activity was determined against $M.$ $grisea$. The QSAR analysis was carried out on a series of 2-phenylimino-1,3-thiazolines. The QSAR results showed the dependence of fungicidal activity on the structural and physicochemical features of 2-phenylimino-1,3-thiazolines. Our results could be used as guidelines for the study of the mode of action and further design of optimal fungicides.