• 제목/요약/키워드: Regioselective substitution

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Development of Macrocyclic Ligands for Stable Radiometal Complexes (안정한 방사금속 착물을 위한 거대고리 리간드 개발)

  • Yoo, Jeong-Soo;Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.4
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    • pp.215-223
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    • 2005
  • Current interest in the regioselective N-functionalization of tetraazacycloalkanes (cyclen and cyclam) stems mainly from their complexes with radioactive metals for applications in diagnostic ($^{64}Cu,\;^{111}In,\;^{67}Ga$) and therapeutic ($^{90}Y$) medicine, and with paramagnetic ions for magnetic resonance imaging ($Gd^{+3}$). Selective methods for the N-substitution of cyclen and cyclam is a crucial step in most syntheses of cyclen and cyclam-based radiometal complexes and bifunctional chelating agents. In addition, mixing different pendent groups to give hetero-substituted cyclen derivatives would be advantageous in many applications for fine-tuning the compound's physical properties. So far, numerous approaches for the regioselective N-substitution of tetraazacycloalkanes and more specifically cyclen and cyclam are reported. Unfortunately, none of them are general and every strategy has its own strong points and drawbacks. Herein, we categorize numerous regioselective N-alkylation methods into three strategies, such as 1) direct substitution of the macrocycle, 2) introductiou of the functional groups prior to cyclization, and 3) protection/iunclionallrationideproteclion. Our discussion is also split into the methods of mono- and tri-functionalization and di-functionalizataion based on number of substituents. At the end, we describe new trials for the new macrocycles which iorm more stable metal complexes with various radiometals, and briefly mention the commercially available tetraazacycloalkanes which are used for the biconjugation of biomolecules.

Synthesis of 6- (Arylamino) -7-Alkylthio -5,8-Quinolinediones for Evaluation of Antifungal Activities

  • Kim, Sung-Hee;Kim, Do-Hee;Lee, In-Kyung;Kwon, Sang-Mee;Jung, Sung-Hee;Ryu, Chung-Kyu
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.166-166
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    • 1996
  • A series of 6-(N-arylamino)-7-alkylthio-5,8-quinolinedione derivatives(SQ1-12) were newly synthesized for the evaluation of antifungal activities. 6-(N-Arylamino)-7-chloro-5,8-quinolinediones (RCKs) were treated with Na$_2$S/(CH$_3$)$_2$SO$_2$ in EtOH In give SQs. RCKs were prepared by regioselective nucleophilic substitution of 6,7-dichloro-5,8-quinolinediones with arylamines. In the presence of CeCl$_3$, the N-arylamino groups were introduced at the 6-position of 5,8-quinolinedione ring by the regioselective substitution. These derivatives 1-12 were tested for antifungal and also antibacterial activities, in vitro, against Candida sp., Aspergillus niger and Trichophyton mentagrophytes. The MIC values were determined by the two-fold dilution method.

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The Synthesis of 6-(N-Arylamino)-7-Chloro-5,8-Quinolinedione Derivatives for Evaluation of Antifugal Activities

  • Ryu, Chung-Kyu;Kim, Hee-Jeong
    • Archives of Pharmacal Research
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    • v.17 no.3
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    • pp.139-144
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    • 1994
  • A series of 6-(N-aylamono)-7-chloro-5, 8-quinolinedione derivatives was newly synthesized for the evaluation of antifugal activities. 5-Amino-8-hydroxy-quinoline (II) was treated with $KCLO_3$ in HCl to give 6,7-dichloro-5,8-quinolinediones (III). 6-(N-Arylamino)-7-chloro5,8-quinolinediones 1-13 were prepared by regioselective nucleophilic substitution of III with arylamines. In the presence of $CeCl_3$, the N-arylamono groups were introduced at the 6-position of 5,8-quinolinedione ring by the regioselective substitution. These derivatives 1-12 were tested for natifungal and also antibacterial activites, in vitro, against Canadida albicans, Aspergillus nier, Tricophyton mentagrophytes, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coil. The MIC values were determined by the two-fold agar/steak dilution method. Newly obtained 6-(N-arylamino)-7-chloro5,8-quinolinedione derivatives showed potent antifungal and antibacterial activities. Among these derivatives, 1,3,5,7,8 and 9 showed more potent antifungal activities than fluconazole and griseofulvin. Also most of derivatives were found to be more active than ampicillin against gram-positive bacteria. 1 and 7 showed the very potent antifungal activities. 1 was the most efective in preventing the growth of Candida albicans, Aspergillus niger, Tricophyton mentagrophytes, Bacillus subtills and Staphylococcus aureus at MIC $1.6\;\mu{g/ml}$.

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Regioselective Substitution of 6,7-DichloroQuinoline-5.8-dione: Synthesis, Cytotoxicity, and X-ray crystal stucture of 4a,10.11- Triazabenzo [3.2-a] fluorene-5,6-diones

  • Lee, Hyun-Jung;Park, So-Young;Lee, Chong-Ock;Suh, Myung-Eun
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.342.1-342.1
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    • 2002
  • 6.7-Dicholroquinoline-5.8-dione reacted with 2-aminopyridine derivatives, Out of the four possible products which could be achieved in this reaction. condensation and rearrangement product. 4a.10.11-triazabenzo[3.2-a] fluorine-5.6-dione was obtained as major product. The definite structure was identified with X-ray crystallographic study. (omitted)

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Synthesis and evaluation of antifungal activities of 5-arylamino-6-chloro-4. 7 -dioxoindazoles

  • You, Hea-Jung;Shim, Ju-Yeon;Shon, Eun-Ha;Choi, Ko-Un;Choi, Ik-Hwa;Chae, Mi-Jin;Ryu, Chung-Kyu
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.353.2-353.2
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    • 2002
  • 5-Arylamino-6-chloro-4.7-dioxoindazoles (DZs) were newly synthesized for the evaluation of antifungal activities. The compounds DZs were prepared by regioselective nucleophilic substitution of 5.6-dichloro-4.7-dioxoindazoles with appropriate arylamines in high yield. DZs were tested for their growth inhibitory activities against Candida species and Aspergillus niger. The MIC values were determined by the two-fold dilution method. In general. DZs showed in vitro antifungal activities. Among the tested compounds, DZ1, 3, 6, 7 and 12 showed potent antifungal activities against Candida species and Aspergillus niger. DZ7 was the most effective in preventing the growth of Candida species.

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Synthesis and Antifungal Evaluation of 6-(N-arylamino)-7-methylthio-5,8-quinolinediones

  • Kim, Chung-Kyu;Choi, Jung-Ah;Kim, Sung-Hee
    • Archives of Pharmacal Research
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    • v.21 no.4
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    • pp.440-444
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    • 1998
  • A series of 6-(N-arylamino)-7-methylthio-5,8-quinolinedione derivatives 4a-4l was newly synthesized for the evaluation of antifungal activity. 6-(N-Arylamino)-7-methylthio-5,8-quinolinediones were prepared by regioselective nucleophilic substitution of 6,7-dichloro-5,8-quinolinediones with arylamines in the presence of $Ce^{3+}$, and $Na_2$S/dimethylsulfate. The MIC values of 4a-4l were determined for antifungal susceptibility in vitro against Candida species by agar streak method. The derivatives 4a-4l had generally potent antifungal activities against all human pathogenic fungi. Especially they had the most potent activity against C. krusei at 12.5-0.8 $\mu\textrm{g}$/ml. Compounds 4d, 4g, 4h, 4j and 4k had more potent antifungal activities than fluconazole. Compounds 4g and 4h completely inhibited the fungal growth at 0.8-6.3 $\mu\textrm{g}$/ml against all Candida species, while fluconazole inhibited the growth at 25 $\mu\textrm{g}$/ml. The compounds such as 4g and 4h containing an N-(4-bromo-2-methylphenyl)- or N-(4-bromo-3methylphenyl)amino substituent exhibited the most potent antifungal activities.

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