• 대한화학회지
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• 제45권5호
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• pp.454-460
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• 2001

3-Methoxycarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline(7)을 hydrazine hydrate와 반응시켜 3-hydrazinocarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline(8)을 합성하였다. 화합물 8을 alkyl (ethoxymethylene)cyanoacetate류와 반응시켜 [(quinoxalin-2-ylidene)ethanoyl]-1H-pyrazole류(9)를 합성하였고, 화합물 9b를 N-alkylaniline류와 반응시켜 N-alkyl-(quinoxalin-2-ylidene)-N-phenylethanamide류(10)를 합성하였다. 얻어진 화합물 9, 10은 용액에서 enamine 형과 methylene imine 형 사이에 토토머화 현상을 나타내었는데, 이들의 토토머비를 $^1H$ NMR 로서 측정하였다.

• 한국응용과학기술학회지
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• 제8권2호
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• pp.145-151
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• 1991

Hazadous properties were evaluated for Alkyl nitrates such as hexyl nitrate, decyl nitrate, dodecyl nitrate and 2-methyl pentyl nitrate, 2-hexyl ethyl nitrate. The thermochemical properties such as heat of vaporization, boiling point, flash point and kinetic parameter for aliphatic nitrate were measured to determine the hazadous properties of these compounds. The boiling points and heat of vaporization increase as the increase of alkyl chain length in alkyl nitrates. Flash point is a linear function of boiling point as same as alkanes. The rate equation in isothermal decomposition are 1/2 order and compensation effect is found between logarithm of frequency factor the activation energy, then the decomposition preceeds with simlar reaction mechanism for each nitrate.

• 공업화학
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• 제9권1호
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• pp.66-70
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• 1998

정보전자 기기의 디스플레이용 재료로 사용되는 액정/고분자 복합재료의 매트릭스로 사용하기 위한 새로운 선형 및 가교형 측쇄 액정고분자를 제조하기 위하여 필요한 저분자 액정 중간체들을 합성하고 이들의 액정 특성을 살펴보았다. Alkyl spacer의 길이가 다르고 연결기로서 azo기를 그리고 말단기로서 cyano를 공통적으로 가지고 다른 한 말단기로서 bromoalkyl(AZO(n)), azidoalkyl(AZI(n)) 및 amonoalkyl(ALC(n))기를 가지는 저분자 액정 들의 합성을 하였으며 IR, NMR 및 원소분석을 통하여 이를 확인할 수 있었다. 또한 DSC thermogram 및 편광현미경 관찰로부터 이들 저분자 액정들은 모두 일정한 온도 영역에서 네마틱 상의 액정성을 발현하는 것을 알았다. 또한, 저분자 액정 분자들이 spacer 길이, 즉 $-(CH_2)n-$의 n이 짝수 및 홀수로 변화함에 따라 분자 내의 conformation 변화에 따른 $T_{KN}$과 $T_{NI}$의 값이 전형적인 even-odd 변화 현상을 나타내었다.

• 한국응용과학기술학회지
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• 제13권3호
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• pp.61-71
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• 1996

In acid-catalyzed acetal cyclization of long aliphatic aldehydes($R=n-C_7H_{15}$ ; $n-C_9H_{19}$ ; $n-C_{11}H_{23}$) with 1,1,1-tris(hydroxymethyl)propane, 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes were obtained. The final products, sodium 2-alkyl-5-(sulfonatedpropylethermethyl)-5-ethyl-1,3-propanesultion in the presence of sodium hydride. These compounds were a new group of destructible surfactants which were readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved some surface properties such as Krafft point(Kp), critical micelle concentration(cmc), surface tension of aqueous solutions near cmc(${\gamma}_{min}$), foaming power, emulsion power and hydrolysis properties were determined. The destructible surfactants containing 1,3-dioxane ring were synthesized to about $85{\pm}5.5%$ yield. The cmc values of the compounds by ring method were assumed to $0.5{\sim}5.0{\times}10^{-3}mol/L$ range and surface tensions at cmc were $29.5{\sim}33.0dyne/cm$ respectively at $25^{\circ}C$. The foaming power and foam stability were $170{\sim}230mm$ and $52{\sim}135mm$ respectively at $1{\times}10^{-2}mol/L$, foam was occurred rarely below $1{\times}10^{-3}mol/L$. The emulsion property of liquid paraffin was better than that of soybean oil. For hydrolysis property with ph and time, these compounds were decomposed within about 200minutes at $ph1{\sim}2$. Hopefully these compounds are expected to be a good O/W emulsifier that have decomposability in acid and may be used in the process which do not need foaming.

• 약학회지
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• 제43권4호
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• pp.442-446
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• 1999

The synthesis and antimicrobial activity of N-substituted glycyl derivatives of Norfloxacin were described. Norfloxacin was treated with chloroacetyl chloride to yield chloroacetyl norfloxacin (1). This compounds was treated with alkylamines to obtain quinolone carboxylic acids (2-6), which were reacted with pivaloyloxymethyl chloride to get pivaloyloxymethyl quinolone carboxylates (7-11). Free carboxylic quinolones (2-6) showed little stronger activities to their pivaloyloxymethyl esters (7-11). In quinolone analogues, longer alkyl chain compounds showed stronger activities than shorter one.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1727-1728
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• 2006

• Bulletin of the Korean Chemical Society
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• 제21권4호
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• pp.441-445
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• 2000

A new series of three ring type liquid crystalline compounds containing partially fluorinated alkenyl or alkyl side chains together with fluorine substituted cyclohexylbiphenyls were designed and synthesized in this study. The structures of synthe sized compounds were established by 1 H, 13 C and 19 F NMR spectroscopy. The phase transition temperatures of fluorinated liquid crystalline compounds were determined by cross-polarizing mi-croscopy equipped withhot stage. All compounds were found to have nematic liquid crystalline phase with rel-atively low phase transition temperature and wide liquid crystalline temperature range. The dependence of phase transition temperatures on the chainlength falls into three categories; (a) decreasing transition tempera-tures for 4-fluoro-4'-[4-fluoro-4-(1-fluoroalkyl)cyclohexyl]biphenyl (15) series, (b) higher transition tempera-tures for odd numbered chains for 4-fluoro-4'-[4-fluoro-4-(1-fluoroalk-1-enyl)cyclohexyl]biphenyl (14) series, (c) higher transition temperatures for even numbered chains for 4-[4-(1,2-difluoroalk-1-enyl)-4-fluorocyclo-hexyl]-4'-fluorobiphenyl (16) series.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 1998년도 제1회 총회 및 추계학술발표회
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• pp.35-35
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• 1998

• 대한화장품학회지
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• 제24권3호
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• pp.6-16
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• 1998

Ceramides are currently emerging as the major skin care ingredients due to !heir barrier properties in the stratum corneum of the human skin. Thus, major cosmetic companies have developed synthetic ceramide analogs for their own use. In this study, several ceramide mimic compounds , new skin barrier lipids, were designed and synthesized, and their physical and biological properties were investigated to evaluate their skin care capability. Several structures were designed from the variation of hydrophobic alkyl chain and hydrophilic moiety by the use of molecular modeling software. The selected targets were synthesized, and their properties and activities were studied as the pure form, in the emulsion, or in the lamellar mixture containing cholesterol and fatty acid. Some compounds, such as 1,3-bis(N-(2-hydroxyethyl)-palmitoylamino)-2-hydroxypropane, enhanced the restoration of skin barrier damaged by SDS(sodium dodecyl sulfate), and by acetone treatment. The rate of restoration was comparable to that of natural ceramides. The synthesized compounds alleviated SDS induced skin irritation and facilitated lamellar phase liquid crystal formation. The treatment of 1,3-Dis(N-(2-hydroxyethyl)-palmitoylam ino)-2-hyd roxypropane on the acetone damaged skin revealed that the compound promoted the recovery of intercellular lipid lamellar structure of stratum corneum layer. The replacement of palmitoyl groups of the compound with shorter alkyl chain gave lower emulsion viscosity and liquid crystal density, suggesting easier formulation and poorer barrier activity. Most of the synthesized compounds were non-irritable in various toxicological tests proving that they can be safely introduced to the skin care formulations.

• 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.