• 제목/요약/키워드: Intramolecular Cyclization

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

  • 김호식;정원영;최경옥;이성욱;곽삼탁;이만길
    • 대한화학회지
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    • 제46권1호
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    • pp.37-45
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    • 2002
  • 3,6-Dichloro-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(8)또는 6-chloro-3-hydrazino-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(9)을 치환 아닐린류, 슬파제 및 heteroacyl chloride류와 반응시켜 2-(pyrazol-1-yl)quinoxaline류(10-12)를 합성하였다. 그리고 화합물 9를 alkyl (ethoxymethylene)cyanoacetate류와 반응시켜 분자내 고리화반응에 의하여 2,3-di(pyrazol-1-yl)quinoxaline류(13)를 합성하였다.

새로운 Quinoxaline류의 합성과 토토머화 현상 (제1보) (Synthesis and Tautomerism of Novel Quinoxalines (Part I))

  • 김호식;김진희
    • 대한화학회지
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    • 제47권3호
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    • pp.241-249
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    • 2003
  • 3-(1-Ethoxycarbonyl)ethyl-1,2-dihydro-2-oxoquinoxaline(8)을 hydrazine hydrate와 반응시켜 3-(1-hydrazinocarbonyl)ethyl-2-hydroxyquinoxaline(9)을 합성하였고, 화합물 9를 치환 벤즈알데하이드류 또는 heteroaryl aldehyde류와 반응시켜 2-hydroxyquinoxaline류(10-12)를 합성하였다. 또한 화합물 9를 alkyl (ethoxymethylene)- cyanoacetate류 또는 ethoxymethylenemalononitrile과 반응시켜 분자내 고리화반응에 의하여 5-amino-1-[2-(3-hydroxyquinoxalin-2-yl)propanoyl]-pyrazole류(13)를 합성하였다. 얻어진 화합물 10-13은 dimethyl sulfoxide 용액에서 lactam형과 lactime형 사이에 토토머화 현상을 나타내었는데, 이들의 토토머 비를 $^1H$ NMR로서 측정하였다. 그리고 합성한 화합물들에 대한 제초력과 살균력도 조사하였다.

Facile Formation of Unexpected [m,6,n]-tricyclic Spiranes via Intramolecular [3+2] Cyclization of Platinum-bound Pyrylium with Alkenes

  • Oh, Chang-Ho;Tak, Sang-Yong;Lee, Ji-Ho;Piao, Lanhua
    • Bulletin of the Korean Chemical Society
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    • 제32권spc8호
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    • pp.2978-2980
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    • 2011
  • Enynals bearing an olefinic pendant were successfully cyclized via Huisgen-type [3+2] cycloaddition to the tetracyclic Pt-carbene complexes which would undergo insertion into a C-H bond of the ${\beta}$-position to afford the fused cyclopropane intermediates. Their tandem rearrangement afforded diverse types of spiranes depending on the tethered alkenes of the enynals.

2(2',2'-디에톡시 에틸)아미노벤즈아미드 유도체의 고리화반응(II) (Cylization Reaction of 2 (2', 2'-diethoxy ethyl) Aminobenzamide derivatives (II))

  • 유희원;이진화;서명은
    • 약학회지
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    • 제33권4호
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    • pp.246-252
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    • 1989
  • 2-Amino-1-N-methyl benzamide, 2-N-benzyl amino benzamide, 2-N-phenyl amino benzamide of 2-amino benzamide derivatives were reacted with ${\alpha}-bromo$ acetaldehyde diethyl acetal in basic condition. 2-N-alkylated products were prepared from 2-amino-1-N-methyl benzamide and 2-N-phenyl amino benzamide. 1-N-benzyl-1.4-benzodiazepin-5-one was prerpared from 2-N-benzyl aminobenzamide via intramolecular cyclization. However, 2-amino-1-N-methyl benzamide with sodium amide did not react to 1.4-benzodiazepin-5-one derivative but 3-methyl-quinazoline-2.4-dione was obtained.

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Photochemistry of 1-(o-substituted -phenyl)-2-pentamethyldishilanyl Ethynes

  • Shim, Sang-Chul;Park, Seung-Ki
    • Journal of Photoscience
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    • 제6권1호
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    • pp.13-19
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    • 1999
  • Irradiation of 1-(o-allyloxyphenyl)-2-pentamethyldisilanylenthyne 2a in methanol yields two 1 : 1 photoaddition products 3 and 4 via silacyclopropene intermediate. Photolysis of 2a with acetone in deaerated methylene chloride yields site specific and regioselective 1 : 1 adducts 6 ad 7 via silacyclopropene and 1-sila-1, 2-propdiene intermediate, respectively. Photolysis of 2a and 1-(o-(3', 3'-dimethyl-2'-propenylox)phenyl)-2-pen-tamethyldisilanylethyone 2b in benzene provides novel stereoselevtive intramolecular cyclization products 10 and 11, respectively. Irradiation of 1-(o-acetoxyphenyl)-2-pentamethyldisilanyl ethyne 2c in benzene yields the photo-Fries rearrangement products 18 and 19 and a photoproduct 17 via silacyclopropene intermediate. Photolysis of 1-(o-methoxycarbonlymethoxyphenyl)-2-pentamethyl disilanylenthyne 2d in benzene provides a novel intramolecular cycloaddition product 25 and 1-(o-methoxycarbonylemthoxiyphenyl)-2-trimethylsilylethyne 26 via silacyclopropene intermediate.

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A Novel Photoreaction of (2-Hydroxyethoxyphenyl)pentamethyldisilane

  • Park, Seung Ki;Seong, Won-Je
    • Bulletin of the Korean Chemical Society
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    • 제30권6호
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    • pp.1331-1336
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    • 2009
  • Photolysis of (2-hydroxyethoxyphenyl)pentamethyldisilane 2 in benzene provides a novel intramolecular cyclization photoproduct 9 which was probably formed from the intramolecular reaction to form a seven-membered ring in silatriene intermediate 7 and then the photochemical disrotatory ring closure of 1,3-butadiene moiety to cyclobutene. Irradiation of 2 in methanol afforded photoproducts 5 and 6 which were formed by the nucleophilic attack of methanol to $\beta$ or $\alpha$ silicon atom in pentamethyldisilanyl group of the photoexcited state of 2. Compounds 10 and 11 were also formed by the same way as in the formation of the photoproducts 5 and 6 in the photolysis of (2-allyloxyethoxyphenyl)pentamethyldisilane 3 in methanol solvent. Photoreaction of (2-acetoxyethoxyphenyl) pentamethyldisilane 4 in methanol gave a photoproduct 12 which was formed via the elimination of dimethylsilylene species in the photoexcited state of 4.

Recent Liquid Crystal Material Development for VA-TFT

  • Bremer, Matthias
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1067-1070
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    • 2005
  • A large size flat panel LCD-TV must fulfill different requirements than a desktop LCD-monitor: The contrast must be much larger, the viewing angle should be as wide as possible and the switching times must be shorter to allow moving pictures to be displayed naturally. The "Vertically Aligned" technology is most promising to realize such a product. LC-material development for this technology began at Merck about 10 years ago. New materials based on the 1,1,6,7-tetrafluoroindane skeleton were recently synthesized via ortho-metallation and intramolecular Heck cyclization followed by an oxidative fluorination procedure. The materials offer improved properties over liquid crystals currently employed in flat panel LCD-TVs.

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A Facile One-Pot Operations of Reduction and Allylation of Nitrobenzaldehydes Mediated by Indium and Their Applications

  • Cho, Yong-Seo;Kang, Kyung-Ho;Cha, Joo-Hwan;Choi, Kyung-Il;Pae, Ae-Nim;Koh, Hun-Yeong;Chang, Moon-Ho
    • Bulletin of the Korean Chemical Society
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    • 제23권9호
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    • pp.1285-1290
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    • 2002
  • Various nitrobenzaldehydes were simultaneously allylated and reduced using indium in the presence of HCl in aqueous media to give compounds having both functionality of homoallylic alcohol and aromatic amine. Sequential protection of the amino gro up and oxidation of the anilinyl homoallylic alcohol provided useful precursors of heterocyclic compounds such as dihydroindolones and dihydroquinolones, which could be efficiently synthesized through intramolecular cyclization reaction.