• 제목/요약/키워드: Heterocyclic

검색결과 315건 처리시간 0.022초

Reactions with Heterocyclic Amidines $(Vl)^1$: Synthesis of some new sym. and assym. pyrazolotriazines and pyrazolo[4,5-e]pyrimidine derivatives

  • Ali Elagamey, Abdel Ghani
    • Archives of Pharmacal Research
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    • 제10권3호
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    • pp.173-178
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    • 1987
  • Several new pyrazolo [1, 5-a]-S-triazine, pyrazolo [4, 5, -elpyrimidine, pyrazolo [1, 5-a] pyrimidine derivatives were synthesized via condensation of 3-antipyrinyl-5-amino-pyrazole (2) with $\beta$$-bifunctional reagents. The azo analogues of pyrazolo [1, 5-a] pyrimidines ; i. e. pyrazolo [5, 1, c]-as-triazine and pyrazolo[5, 1, -c]-as-benzotriazine were synthesized by coupling of diazotized 2-with agents containing active hydrogen.

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Synthesis and Biological Effects of Some 5-Heterocyclicmethyl-2'-deoxyurdines

  • Kwak, In-Young;Ryu, Eung K.
    • Archives of Pharmacal Research
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    • 제13권4호
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    • pp.306-309
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    • 1990
  • The synthesis of 5-hyterocyclimethyl-2'-deoxyuridines (4a-f) has been accomplished by displacement reaction of 5-(bromomethyl)-3', 5'-di-O-acetyl-2'-deoxyuridine with heterocyclic compounds, followed by removal of acetyl protecting group with methanolic ammonia. The compoudns synthesized were evaluated the inhibitory effects on L1210 cell probiferation and antiviral activities against Herpes simplex virus type 1 (HSV-1) None of the compounds exhibited sufficient biological activities.

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신규 2,3-dicyanopyrazine유도체의 합성과 특성 (Synthesis and characteristics of 2,3-dicyanopyrazine derivatives.)

  • Lee, Bum-Hoon;Jaung, Jae-Yun
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2001년도 가을 학술발표회 논문집
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    • pp.247-250
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    • 2001
  • 2, 3-Dicyanopyrazine derivatives have been synthesized by condensation of diaminomaleonitrile(DAMN) and a -diketone compounds. Diaminomaleohitrile (DAMN) is well known as a tetramer of hydrogen cyanide and a useful compound in the chemical industry not on]y as a starting material for synthesis of various heterocyclic compounds but also as an intermediate for synthesis of glycine, adenine, guanine et al. (omitted)

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Nitrogen mustard류의 합성에 관한 연구 (Studies on the synthesis of nitrogen mustard derivatives)

  • 채동규;천문우;채건
    • 약학회지
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    • 제13권4호
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    • pp.139-143
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    • 1969
  • In order to diminish the side effects of nitrogen mustard on cancertherapy, alkyl and heterocyclic radicals were introduced to nitrogen mustard base. The prepared new nitrogen mustard derivtives are N-bis($\beta$-chloroethyl)-2-furamide, 5-nitro-N-bis($\beta$-chloroethyl)-2-furamide and N-bis($\beta$-chloroethyl) ortamide hydrochloride.

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Benzoin Condensation Reactions of 5-Membered Heterocyclic Compounds Catalyzed by Thiazolium Salts

  • Chang Kiu Lee;Jin Soon Gong;Sin Kwan Seog;Jong-Gab Jun
    • Bulletin of the Korean Chemical Society
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    • 제14권1호
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    • pp.29-31
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    • 1993
  • Benzoin condensation reactions of furfurals and thiophenecarboxaldehydes in the presence of substituted benzyl and alkyl thiazolium salts were examined in order to improve the yield of the reaction and to examine the effect of the electronic nature of the catalysts. Thiophene derivatives gave thenils as the major products in low yields while furan derivatives gave only furoins in moderate to high yields.

Synthesis of Cephalosporins Having a Heterocyclic Group at the C-3 Position

  • Myung Hee Jung;Kul-Woong Cho;Wan Joo Kim;Joon-Seob Shin;Choong Sil Park
    • Bulletin of the Korean Chemical Society
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    • 제14권1호
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    • pp.32-38
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    • 1993
  • 3-(3-Bromotetrahydrofuran-2-yl)-3-cephem 7 was obtained from 3-(2-hydroxyethyl)vinyl-3-cephem 6 by the cyclization reaction using N-bromosuccinimide. Compound 5 was prepared by Wittig reaction, namely a coupling of cephem-derived triphenylphosphonium salt 3 with aldehyde component 4 in the presence of base.

Convenient Procedure for the Reduction of Carboxylic Acids via Acyloxyborohydrides

  • Cho, Byung-Tae;Yoon, Nung-Min
    • Bulletin of the Korean Chemical Society
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    • 제3권4호
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    • pp.149-152
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    • 1982
  • A new convenient method for the reduction of carboxylic acids to the corresponding alcohols via acyloxyborohydrides was explored. Acyloxyborohydrides, prepared from the reaction of various carboxylic acids and sodium borohydride, underwent reduction to the corresponding alcohols readily by the addition of dimethyl sulfate or Lewis acids, such as boron trifluoride etherate and triphenyl borate, presumably through acyloxyboranes. By utilizing this procedure, aliphatic and aromatic acids are rapidly and quantitatively reduced to the corresponding alcohols in terahydrofuran either at room temperature (or at $65^{\circ}$). This procedure provides selective reduction of carboxylic acids in the presence of halogen, nitro, and heterocyclic rings such as furan and thiophene.

Synthesis of Selenoflavonoids

  • Kim, Dong-Myung;Jeong, Jin-Hyun
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.182.1-182.1
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    • 2003
  • Flavonoids with oxygen atoms are known to have potent biological effect.They have been studied long as major antioxidants which protect cell membranes. Recent medical surveys show that increased intake of selenium decreases the risk of breast, colon, lung and prostrate cancer by preventing free radical generation. The flavonoids, isoflavonoids, and coumarins which form the bulk of these compounds are very polar and have limited use as drugs which have to pass through BBB(Brain Blood Barrier)The non-polar property is increased by exchange oxygen to selenium as a part of heterocyclic compound. (omitted)

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Cyanoacetic Acid Hydrazide in Heterocyclic Synthesis: A New Route for the Synthesis of Several Annelated Pyran Derivatives

  • Eldin, Sanaa M.;El-Din, Asmaa A. Magd;Basyouni, Wahid M.
    • Archives of Pharmacal Research
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    • 제16권4호
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    • pp.318-321
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    • 1993
  • Cyanoaccetic acid hydrazide reacted with some 2-pyrazolin-5-one, isoxazol-5-one and 2-thiazolin-4-one and their ylidene derivatives to yield several new annelated pyran heterocycles. Structures wre established on the basis of elementary analyses and spectral data studies in addition to synthesis via other routes.

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5원자 헤테로고리 화합물을 이용한 $Mg^{2+}$의 정량 (Determination of $Mg^{2+}$ using 5-membered Heterocyclic Compound)

  • 서무룡;이심성;김재상;박태명
    • 분석과학
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    • 제6권3호
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    • pp.307-311
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    • 1993
  • 5원자 헤테로고리를 포함하는 열린고리형의 ionophore를 합성하였다. 이 때 합성한 ionophore를 착화제로 이용하여 수용액 중의 $Mg^{2+}$을 염석추출법으로 추출하여 원자 흡광 광도법으로 정량하였다. Acetate 완충용액으로 pH를 4.2로 조절한 $Mg^{2+}$를 포함하는 수용액에 ionophore-AN 용액을 넣어 $Mg^{2+}$-ionophore 착물을 형성시킨 다음, 염석제를 첨가하여 유기층으로 추출하고, 유기층의 착물의 흡광도를 원자 흡광 광도계로서 측정하여 $Mg^{2+}$를 정량하였다. 최적 추출 조건을 조사해 본 결과, 최적 pH는 2.5~5.0이었으며, 염석제인 황산암모늄[$(NH_4)_2SO_4$]의 양은 5g 이상이면 정량적으로 추출되었다. 또한 $Mg^{2+}$과 ionophore의 착물 조성비는 1:2이었다. $Mg^{2+}$의 정량범위는 0.24ppm~2.4ppm이었으며 $Ca^{2+}$이온 및 EDTA의 방해효과가 크게 나타났다.

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