• 제목/요약/키워드: bromo

검색결과 330건 처리시간 0.03초

Carbonylation of 1-Bromo-2,6-bis(bromomethyl)benzene Catalyzed by Cobalt Carbonyl

  • Sang Chul Shim;Shin Ae Chae;Dong Yeob Lee;Young Zoo Youn;Jae Goo Shim;Chil Hoon Doh
    • Bulletin of the Korean Chemical Society
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    • 제14권4호
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    • pp.481-485
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    • 1993
  • Dialkyl 1-bromobenzene-2,6-diacetates were easily prepared by the carbonylation of the moiety of benzylic bromide in 1-bromo-2,6-bis(bromomethyl)benzene with alcohol in the presence of NaOAc< TEX>${\cdot}$3H$_2$O and a catalytic amount of Co$_2$(CO)$_8$under the atmospheric pressure of carbon monoxide at room temperature in excellent yield. Alkyl 2,6-bis(alkoxymethyl)benzoates were obtained by the carbonylation of the moiety of aryl bromide in 1-bromo-2,6-bis(alkoxymethyl)-benzene, which derived from 1-bromo-2,6-bis(bromomethyl)benzene, alcohol, NaOR, and CH$_3$I under the same conditions. Alkyl 2,6-bis(carboxymethyl)benzoate was also obtained in a trace amount for 24 hrs at room temperature.

Bromocycloetherification Using NBS-Acetonitrile

  • Cook, Chae-Ho;Cho, Youn-Sang;Jew, Sang-sup;Jung, Young-Hoon
    • Archives of Pharmacal Research
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    • 제8권1호
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    • pp.39-41
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    • 1985
  • Bromocycloetherification of a series of 3-and 4-olefinic alcohols using NBS-acetonitrile gave corresponding bromo-tetrahydrofuran with high regio and steroselectivity.

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A Novel Photonuclease; Bromofluoroacetophenone-Pyrrolecarboxamides

  • Jeon, Ra-Ok
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.236.1-236.1
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    • 2003
  • Bromofluoroacetophenone derivatives which produce fluorine substituted phenyl radicals that cleave DNA upon excitation were investigated as a novel photonuclease. Pyrrolecarboxamide-conjugated bromofluoroacetophenones: 4'-bromo-2'-fluoroacetophenone and 2' -bromo-4'-fluoroacetophenone were synthesized and their DNA cleaving activities and sequence selectivities were determined. (omitted)

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6,6-Dibromopenicillanic acid 1,1-Dioxide 분자내 탄소 6-위치 브롬기의 전극촉매 수소화반응과 전극반응기구 (Electro-Catalytic Hydrogenation and the Electrode Reaction Mechanism of the Carbon-6-Bromo groups of 6,6-Dibromopenicillanic acid 1,1-Dioxide)

  • 김일광;이영행;이채호
    • 대한화학회지
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    • 제35권2호
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    • pp.165-171
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    • 1991
  • 6,6-dibromopenicillanic acid 1,1-oxide(DBPA)의 6위치 dibromo기의 전기화학적 환원을 direct current, differential pulse polarography, cyclic voltammetry, 조절전위 전기량법으로 연구하였다. DBPA 환원과정은 2단계-0.48, -1.62 volts)에서 모두 완전비가역으로 2전자씩 이동하는 EC, EC 반응기구로 진행하였다. 조절전위 전기분해를 이용하여 6-bromo-PA와 6,6-dihydro-PA를 단계적으로 합성하였으며, pH 변화에 다른 폴라로그램의 해석과 생성물 분석의 결과를 바탕으로 전기화학적 반응기구도 제안하였다.

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Growth Inhibition and G2/M Phase Cell Cycle Arrest by 3,4,5-Trimethoxy-4'-bromo-cis-stilbene in Human Colon Cancer Cells

  • Heo, Yeon-Hoi;Min, Hye-Young;Kim, Sang-Hee;Lee, Sang-Kook
    • Biomolecules & Therapeutics
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    • 제15권2호
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    • pp.95-101
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    • 2007
  • Resveratrol (3,5,4’-trihydroxy-trans-stilbene), a naturally occurring phytoallexin abundant in grapes and several plants, has been shown to be active in inhibiting proliferation and inducing apoptosis in several human cancer cell lines. On the line of the biological activity of resveratrol, a variety of resveratrol analogs were synthesized and evaluated for their growth inhibitory effects against several human cancer cell lines. In the present study, we found that one of the resveratrol analogs, 3,4,5-trimethoxy-4’-bromo-cis-stilbene, markedly suppressed human colon cancer cell proliferation (EC$_{50}$ = 0.01 ${\mu}$g/ml), and the inhibitory activity was superior to its corresponding trans-isomer (EC$_{50}$ = 1.6 ${\mu}$g/ml) and resveratrol (EC$_{50}$ = 18.7 ${\mu}$g/ml). Prompted by the strong growth inhibitory activity in cultured human colon cancer cells (Col2), we investigated its mechanism of action. 3,4,5-Trimethoxy-4’-bromo-cis-stilbene induced arrest of cell cycle progression at G2/M phase and increased at sub-G1 phase DNA contents of the cell cycle in a time- and dose-dependent manner. Colony formation was also inhibited in a dose-dependent manner, indicating the inhibitory activity of the compound on cell proliferation. Moreover, the morphological changes and condensation of the cellular DNA by the treatment of the compound were well correlated with the induction of apoptosis. These data suggest the potential of 3,4,5-trimethoxy-4’-bromo-cis-stilbene might serve as a cancer chemotherapeutic or chemopreventive agent by virtue of arresting the cell cycle and inducing apoptosis for the human colon cancer cells.

가스크로마토그라피 분석을 통한 $\alpha$-브로모-$\omega$ -플루오로알칸의 효율적 합성 (Effective Synthesis of $\alpha$--Bromo-$\omega$ -fluoroalkane with Analysis of Gas-chromatography)

  • 유국현
    • 대한화학회지
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    • 제39권5호
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    • pp.414-420
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    • 1995
  • 디브로모알칸, AgF 및 tetrabutylammoniumbromide(TBABr)를 acetonitrile 용매하에서 $82^{\circ}C$에서 20분간 반응시켜 19~55%의 수율로 $\alpha$-브로모-$\omega$-플르오르알칸을 합성하였다. 반응 조건은 가스 크로마토그라피를 이용하여 조절하였으며, 반응 생성물인 $\alpha$-브로모-$\omega$-플르오르알칸, 디플르오로알칸, 플르오로알켄 및 브로모알켄을 1^H$ NMR 및 $19^F$ NMR로 확인하였다.

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Dynamic Kinetic Resolution of α-Bromo Carboxylic Acid Derivatives in Asymmetric Nucleophilic Substitution with Chiral α-Amino Esters

  • Chang, Ji-Yeon;Shin, Eun-Kyoung;Kim, Hyun-Jung;Kim, Yong-Tae;Park, Yong-Sun
    • Bulletin of the Korean Chemical Society
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    • 제26권6호
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    • pp.989-992
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    • 2005
  • Dynamic kinetic resolution of $\alpha$-bromo carboxylic acid derivatives in nucleophilic substitution with chiral $\alpha$-amino ester nucleophiles in the presence of TBAI and DIEA has been investigated for stereoselective syntheses of 1,1'-iminodicarboxylic acid derivatives. Nucleophilic substitutions with various chiral $\alpha$-amino esters gave iminodiacetates 2-8 with stereoselectivities up to 87 : 13 dr. Also, the reactions of N-($\alpha$-bromo-$\alpha$-phenylacetyl)-L-alanine methyl ester with L-alanine, D-alanine and glycine methyl ester nucleophiles afforded N-carboxyalkyl dipeptide analogues 10-12 up to 90 : 10 dr.

Synthesis of Various Polymeric Prodrugs of Ibuprofen with PEG and Its Derivative as Polymeric Carriers

  • Lee, Chan-Woo
    • Macromolecular Research
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    • 제12권1호
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    • pp.63-70
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    • 2004
  • We have synthesized various types of poly(ethylene glycol) (PEG)-ibuprofen conjugates by the nucleophilic substitution of bromo-terminated PEG with ibuprofen-Cs salt; PN (Pluronic) was also used in place of PEG. All the bromo-terminated PEGs and PN were obtained in high yield. Conversions of the terminal hydroxyl groups to bromo-termini were quantitative, as were the drug conjugation processes. The Ι$_1$$_3$values obtained from solutions of the ibuprofen-conjugated prodrugs are summarized in relation to those of ibuprofen in water and in aqueous solutions of the original PEG, PN, and several ordinary surfactants. We believe that the fully hydrophilic PEG is completely hydrated and forms no hydrophobic pocket by segment aggregation. These results indicate that the probe environment is significantly hydrophobic, particularly in the solution of prodrug PN, for which the ratio is similar to that obtained from typical micelles of surfactants. The results suggest, therefore, that the present synthetic method is very useful for preparing PEG-based prodrugs from pharmaceuticals having carboxyl functionalities.