• Title, Summary, Keyword: Quinoxalines

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Synthesis of Novel 1,2-Diazepino[3,4-b] quinoxalines and pyridazino[3,4-b] quinoxalines (새로운 1,2-다이아제피노 [3,4-b]퀴녹살린류와 피리다지노 [3,4-b] 퀴녹살린류의 합성)

  • Kim, Ho-Sik;Lee, Seong-Uk;Jeong, Geuk;Lee, Man-Kil;Kurasawa, Yoshihisa
    • YAKHAK HOEJI
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    • v.44 no.4
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    • pp.325-333
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    • 2000
  • The 1,3-dipolar cycloaddition reaction of the quinoxaline 4-oxides 2 with 2-chloroacrylonitrile gave the 2,3-dihydro-1H-1,2-diazepino[3,4-b]quinoxalines 3, which were converted into the 2,3,4,6-tetrahydro-1H-1,2-diazepino[3,4-b]quinoxalines 5-7. The reaction of compounds 3 with selenium dioxide in acetic acid/water resulted in ring transformation to give the 1,4-dihydro-4-oxopyridazino[3,4-b]quinoxalines 8.

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A Selective Synthesis of Isoxazolo[2,3-${\alpha}$]quinoxalines and Pyrrolo[1,2-${\alpha}$]quinoxalines by 1,3-Dipolar Cycloaddition Reaction (1,3-쌍극성 고리화 첨가반응에 의한 Isoxazolo[2,3-${\alpha}$]quinoxaline류와 Pyrrolo[1,2-${\alpha}$]quinoxaline류의 선택적인 합성)

  • Kim Ho Sik;Nam Soon Hwa;Kurasawa Yoshihisa
    • Journal of the Korean Chemical Society
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    • v.34 no.5
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    • pp.469-475
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    • 1990
  • The reaction of 2,6-dichloroquinoxaline (13) with m-chloroperbenzoic acid gave 2,6-dichloroquinoxaline 4-oxide (14), whose reaction with pyrrolidine or indoline provided 2-substituted 6-chloroquinoxaline 4-oxides (15). The isoxazolo[2,3-a]quinoxalines (16) and pyrrolo[1,2-a]quinoxalines (17) were selectively synthesized from the 2-substituted 6-chloroquinoxaline 4-oxides (15) and dimethyl acetylenedicarboxylate. Moreover, the pyrrolo[1,2-a]quinoxalines (17) were found to be produced by the ring transformation of the isoxazolo[2,3-a]quinoxalines (16).

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Synthesis of Triazoloquinoxalines as Antitubercular Agents

  • Sekhar, Kondapalli Venkata Gowri Chandra;Rao, Vajja Sambasiva;Kumar, Dalip
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2657-2660
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    • 2011
  • 1,2,4-Triazoles and quinoxalines were found to display various pharmacological activities. Hence a series of 1-aryl-4-methyl-1,2,4-triazolo[4,3-a]quinoxalines were synthesized. Due to various advantages of organic reactions under solvent-free conditions these compounds were developed using iodobenzene diacetate under solvent-free conditions. The synthesized compounds were characterized by elemental microanalysis, infrared spectroscopy, $^1H$ NMR, $^{13}C$ NMR and HRMS. All the synthesized compounds were investigated for their antitubercular activity and 5g was found to the most active compound.

Synthesis and Antimicrobial Activity of Certain Novel Quinoxalines

  • Refaat, Hanan-M.;Moneer, Ashraf-A.;Khalil, Omneya-M.
    • Archives of Pharmacal Research
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    • v.27 no.11
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    • pp.1093-1098
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    • 2004
  • In this study, certain 3-methyl-2-[4-(substituted amino carbonyl)anilino] quinoxalines, (2a-d) and (3a-d), were synthesized from the new key compound 2-[4-(ethoxycarbonyl)anilino]-3-methyl quinoxaline (1). In addition, a series of 2-[4-(arylidene hydrazinocarbonyl)anilino]-3-methyl quinoxalines (5a-e), as well as their cyclized oxadiazolinyl derivatives (6a-e), and a series of 2-[4-$N^2$-acylhydrazinocarbonyl)anilino]-3-methyl quinoxalines (7a-d), as well as their cyclized oxadiazolyl derivatives (8a-d) were also prepared. Some of these derivatives were evaluated for antimicrobial activity in vitro. It was found that all the selected compounds exhibit antimicrobial activity and that compound 5b had a broad spectrum of activity.

Synthesis of 2-(Pyrazol-1-yl)quinoxalines and 2,3-Di(pyrazol-1-yl)quinoxalines (2-(Pyrazol-1-yl)quinoxaline류 및 2,3-Di(pyrazol-1-yl)quinoxaline류의 합성)

  • Kim, Ho-Sik;Jeong, Won-Young;Choi, Kyung-Ok;Lee, Seong-Uk;Kwag, Sam-Tag;Lee, Man-Kil
    • Journal of the Korean Chemical Society
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    • v.46 no.1
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    • pp.37-45
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    • 2002
  • The reaction of 3,6-dichloro-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(8) or 6-chloro-3-hydrazino-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(9) with substituted anilines, sulfa drugs and heteroacyl chlorides gave 2-(pyrazol-1-yl)quinoxalines(10-12). The reaction of compound 9 with alkyl (ethoxymeth-ylene) cyanoacetates resulted in the intramolecular cyclization to give 2,3-di(pyrazol-1-yl)quinoxalines(13).

Synthesis of Tetrazolo[1,5-a]quinoxalines with Antimicrobial Activity (항균성을 가진 Tetrazolo[1,5-a]quinoxaline류의 합성)

  • Kim, Ho Sik;Kim, Dong Eun;Yoshihisa Kurasawa
    • Journal of the Korean Chemical Society
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    • v.45 no.4
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    • pp.325-333
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    • 2001
  • The 4-substituted tetrazolo[1,5-a]quinoxalines were synthesized from 4-chlorotetrazolo-[1,5-a]quinoxaline(8) or 4-hydrazinotetrazolo[1,5-a]quinoxaline(9). Refluxing of the tetrazolo[1,5-a]quinoxaline(12) in N,N-dimethylformamide gave the 1,2,4-triazolo[3,4-c]tetrazolo[1,5-a]quinoxaline(13), which was also obtained by the reaction of compound 9 with ethyl chloroformate in N,N-dimethylformamide. The reaction of compound 9 with isothiocyanates in ethanol provided the tetrazolo[1,5-a]quinoxalines(14), whose reaction with dimethyl acetylenedicarboxylate afforded the tetrazolo[1,5-a]quinoxalines(15). The tetrazolo [1,5-a]quinoxalines(18) were obtained by the reaction of compound 9 with alkyl (ethoxymethylene)cyanoacetates. Some of the compounds showed antibacterial, antifungal or algicidal activities against some strains.

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Synthesis of Quinoxaline Derivatives Using TiO2 Nanoparticles as an Efficient and Recyclable Catalyst

  • Alinezhad, Heshmatollah;Tajbakhsh, Mahmood;Salehian, Fatemeh;Biparva, Pourya
    • Bulletin of the Korean Chemical Society
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    • v.32 no.10
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    • pp.3720-3725
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    • 2011
  • $TiO_2$ nanoparticles were synthesized and characterized by SEM and XRD techniques. The $TiO_2$ nanoparticles were employed as a recyclable, inexpensive and efficient catalyst for the synthesis of substituted quinoxalines in high to excellent yields and in relatively short duration.

Synthesis and Tautomerism of Novel Quinoxalines (Part II) (새로운 Quinoxaline류의 합성과 토토머화 현상 (제2보))

  • Ho Sik Kim;Kyung Ok Choi;Woo Sung Lim
    • Journal of the Korean Chemical Society
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    • v.47 no.4
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    • pp.345-353
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    • 2003
  • The reaction of 6-chloro-3-methoxycarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline(5) or 3-methoxycarbonylmethylene-6-nitro-2-oxo-1,2,3,4-tetrahydroquinoxaline(6) with hydrazine hydrate gave 3-hydrazinocarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxalines(7, 8). The reaction of compound 7 or 8 with substituted benzaldehydes or heteroaromatic aldehydes afforded quinoxalines(9-14). Compounds showed the tautomerism between the enamine and methylene imine forms, and between the enamine, methylene imine and enaminol forms in dimethyl sulfoxide solution. The tautomer ratios were determined by the 1H NMR.