• 한국자기공명학회논문지
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• 제22권4호
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• pp.115-118
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• 2018

Dipyrromethane 2 functionalized with 3-chloropropyl group on the meso carbon undergoes an unusual intramolecular electrophilic aromatic substitution reaction in the presence of $NaN_3$ instead of a simple nucleophilic substitution reaction. As a result, a new chiral dipyrromethane 1 was synthesized. In this reaction, the ${\beta}$-carbon of the pyrrole ring functions as a nucleophile while the carbon next to the chlorine atom acts as an electrophile. Interestingly, this reaction progresses even in the absence of an acid catalyst. Compound 1 was fully characterized by $^1H-^1H$ and $^1H-^{13}C$ COSY NMR spectroscopic analyses and the high resolution EI mass spectrometry.

• 약학회지
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• 제33권5호
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• pp.273-279
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• 1989

2,3-Dichloro-1,4-naphthoquinone was reacted with o-fluoroaniline, p-sulfadiazine, p-acetoanline, N,N-dimethyl-1,4-phenylenediamine as a nucleophilic substitution to form 2-chloro-3-(N-arylamino)-1,4-naphthoquinones (1.-6.) in good yield. 2,3-Dibromo-1,4-naphthoquinone was also reacted with o-fluoroaniline, m-aminobenzoic acid, m-chloroaniline, morpholine, p-acetoaniline, N,N-dimethyl-1,4-phenylenediamine as a nucleophilic substitution to give 2-bromo-3-(N-arylamino)-1,4-naphthoquinones (7.-12.). These new compounds are expected to have a biological activities such as anticoagulant, cytotoxic.

• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.668-670
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• 2005

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2294-2298
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• 2009

In present work an attempt was made to synthesize various analogues of levofloxacin by introducing new functionality at carboxylic group position via nucleophilic substitution reaction. For this purpose the carboxylic group at C-6 was esterified and later subjected to nucleophilic attack at the carbonyl carbon by various aromatic amines. Structure of the analogues was confirmed by different techniques i.e. IR, $^1H$ NMR and mass spectrometry. The antibacterial activity of the derivatives was also assessed and compared with the parent against a series of Gram-positive and Gramnegative bacteria. A synergistic as well as antagonistic behavior was observed in these derivatives. Additionally unlike levofloxacin, the derivatives were also found to modulate oxidative burst response of phagocytes exhibiting moderate to significant inhibitory activity.

• Bulletin of the Korean Chemical Society
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• 제12권6호
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• pp.658-661
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• 1991

The gas-phase nucleophilic substitution reaction of pentafluoroanisole with $OH^-$ and ${NH_2}^-$ nucleophiles have been studied theoretically using the AM1 method. Three reaction channels, $S_N2$, IPSO and $S_NAr$ (scheme 1), are all very exothermic so that all are accessible despite the varying central energy barriers which are much lower than the reactants level. In the IPSO and $S_NAr$ channels, the reactants form directly a stable ,${\sigma}$-anion complex which proceeds to form a proton transfer complex via a transition barrier corresponding to a loose ${\pi}$-type complex with the F-(or ${OCH_3}^-$) leaving group. Due to a greater number of probable reaction sites available for $S_NAr$ compared to the other two processes, the $S_NAr$ channel is favored as experimentally observed.

• 약학회지
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• 제39권2호
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• pp.118-130
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• 1995

Aliphatic & aromatic compounds with two nucleophilic functional groups which were chosen as nucleophiles reacted with 2,3-dichloro-1,4-naphthoquinone as a substrate to give cyclized products by nucleophilic vinyl substitution. And the trends in the syntheses of the heterocyclic compounds was studied and expounded. Besides, the biological activities of the products, especially activity as an agricultural chemical, were examined. Moreover 5-aminomethyl-2-pyrrolidinone was synthesized for the purpose of forming a polynuclear heterocyclic compound containing a similar structure of azasteroid. However only one chlorine of 2,3-dichloro-1,4-naphthoquinone was replaced by an amino group of pyrrolidinone and cyclization did not take place.

• 폴리머
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• 제25권6호
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• pp.796-802
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• 2001

나프탈렌을 측쇄로 갖는 새로운 폴리벤즈이미다졸 단량체을 합성하고, 이 단량체를 친핵치환반응에 의해 중합하였다. 4-Methoxy-N-naphthyl-1,2-phenylenediamine과 4-fluoro-benzoyl chloride의 반응으로 N-(4-fluorobenzoyl)-4-methoxy-N'-naphthyl-1,2-phenyl-enediamine이 합성되었고 이로부터 고리화반응 및 demethylation에 의해 단량체인 2-(4-fluoro-benzoyl)-5-hydroxy-1-naphthylbenzimidazole이 얻어졌다. 중합반응은 potassium carbonate를 함유하는 N-cyclohexyl-2-pyrrolidinone (CHP)에서 행해졌다. 생성된 폴리벤즈이미다졸은 N-methyl-2-pyrrolidinone (NMP)에 용해되었고 0.38 dL/g (NMP at $30^{\circ}C$)의 대수 점도를 가졌다. 유리전이온도($T_g$)는 $270^{\circ}C$였고 열중량분석에서 5% 중량감소를 보이는 온도는 질소분위기에서는 $550^{\circ}C$, 공기중에서는 $540^{\circ}C$였다.

• 농약과학회지
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• 제8권4호
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• pp.258-264
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• 2004

효과적인 살충제로 pyrazole 계통의 화합물이 널리 알려졌으며, 이중에 fenpyroximate와 tebufenpyrad는 시판되고 있다. 본 연구에서는 fenpyroximate의 새로운 유도체로써 5-번 위치가 치환된 pyrazole oxime ether를 합성하였다. 본 연구의 핵심 중간체인 4-formyl-5-chloro-pyrazole 2는 ethyl acetoacetate와 methylhyazine의 축합반응으로 얻은 pyrazolone 1을 Vilsmeier-Haack chloroformylation을 통하여 합성하였다. 2에 nucleophilic aromatic substitution 반응을 하여 질소고리화합물이 5-번 위치에 도입된 pyrazole aldehyde 3a-i를 만든 후, 차레로 oxime 화합물 4a-i 그리고 oxime ether 화합물 6a-i를 각각 합성하였다. 합성된 화합물 중에서 6d는 벼멸구 (Brown Planthopper, BPH), 배추좀나방 (Diamondback Moth, DBM), 점박이응애 (Two Spotted Spider Mite, TSSM)에서 높은 활성을 보여주고 있으며, 이는 fenpyroximate의 살충활성과 비슷하였다. 본 결과는 6d가 다양한 곤충 및 응애에 대하여 효과가 우월하여 살충, 살비제로써 개발 가능성을 보여주고 있다.

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.896-900
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• 2000

A study was done on the synthesis of new poly(arylene ether)s and poly(arylenesulfide) with rigid benzoxazole pendants using nucleophilic aromatic substitution reaction. As a new aromatic monomer, 1,4-bis(2-benzox-azolyl)-2,5-difluorobenzene [I] w as synthesized in three steps starting from 1,4-dibromo-2,5-difluorobenzene. A model reaction of difluoro monomer [I] with two equivalents of m-cresol or thiophenol in a typical ether con-densation reaction conditions gave very high yields ( > 93%) of the desired disubstituted product, suggesting the feasibility of polymer formation in these reaction system. Monomer[I] was polymerized with bisphenols and bisbenzenethiol in NMP using K2CO3 as base. The molecular weight of the resulting polymers, however,seemed relatively low according to their solution viscosity values ( ηinh = 0.15-0.29 dL/g). The poly(arylene ether)s were soluble in several common organic solvents including chloroform, pyridine and N,N'-dimethylfor-mamide. The poly(arylene sulfide) was, however, ony soluble in strong acids like sulfuric acid and trifluoro-acetic acid. The glass transition temperatures were found to be 175-215 $^{\circ}C.$ These polymers were stable up to 380-420 $^{\circ}C$ in both nitrogen and air, as determined by the temperature that a significant weight loss began to appear on TGA.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.487-488
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• 2006

Novel bisphenol-based wholly aromatic poly(ether sulfone-ketone) copolymer containing pendant sulfonate groups were prepared by direct aromatic nucleophilic substitution polycondensation of 4,4-difluorobenzophenone, 2,2'-disodiumsulfonyl-4,4'-fluorophenylsulfone (40mole% of bisphenol A) and bisphenol A. Polymerization proceeded quantitatively to high molecular weight in N-methyl-2-pyrrolidinone at $180^{\circ}C$. Organic-inorganic composite membranes were obtained by mixing organic polymers with hydrophilic $SiO_2$ (ca. 20nm) obtained by sol-gel process. The polymer and a series of composite membranes were studied by FT-IR, $^1HNMR$, differential scanning calorimetry (DSC) and thermal stability. The proton conductivity as a function of temperature decreased as $SiO_2$ content increased, but methanol permeability decreased. The nano composite membranes were found to posse all requisite properties; Ion exchange capacity (1.2meq./g), glass transition temperatures $(164-183\;^{\circ}C)$, and low affinity towards methanol $(4.63-1.08{\times}10^{-7}\;cm^2/S)$.