• 약학회지
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• 제33권5호
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• pp.290-295
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• 1989

2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid methyl ester (1) was formylated to 2,6-dimethy-4-(3'-nitrophenyl)-5-formyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (2) in 76% yield. At the elevated temperature, 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-monomethyl ester (3) was also converted into compound 2 in 46% yield. The compound 2 was reduced to 2,6-dimethyl-4-(3'-nitrophenyl)-5-hydroxymethyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (4) in 91% yield. Compound 2 was reacted with triethyl phosphonoacetate to give 2,6-dimethyl-4-(3'-nitrophenyl)-5-(2-ethoxycarbonyl ethenyl)-1,4-dihydropyridine-3-carboxylic acid methyl ester (5) in 50% yield. Reaction between compound 2 and amines (methyl amine, ethylamine, methoxylamine, hydroxyl amine, phenyl hydrazine and 1-amino-4-methyl piperazine) gave six schiff bases 7a, 7b, 7c, 7e, 7f in 81%, 91%, 82%, 81%, 50% and 84% yield, respectively.

• 공업화학
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• 제20권5호
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• pp.532-535
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• 2009

본 연구에서는 식물성 오일의 에스테르화 반응에 초음파에너지를 도입하여 지방산 methyl ester를 제조하였다. 초음파 에너지가 에스테르화 반응에 도입될 경우 반응온도의 가열효과뿐만 아니라 교반효과를 동시에 가져올 수 있어 반응시간 단축 및 지방산 methyl ester 수율의 증가를 가져올 수 있다. 그러나 초음파에너지가 에스테르화 반응에 도입될 때 연속적인 초음파에너지의 조사로 인한 반응온도의 계속적인 상승이 문제점으로 확인되었다. 따라서 본 연구에서는 cooling system을 이용하여 반응온도의 상승을 억제하여 실험을 수행한 결과 기존공정보다 빠른 30 min 만에 93%의 지방산 methyl ester 수율을 확인하였다.

• 약학회지
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• 제33권4호
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• pp.219-225
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• 1989

2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-methyl 5-(2'-methylthio)ethyl ester methyl iodide salt (7a) was hydrolyzed by treatment with NaOH in aquous EtOH solution to give 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid mono methyl ester (2b) in 88% yield. By the same procedure, 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridinine-3,5-dicarboxylic acid 3-mono isopropyl ester (2c), 2,6-dimethyl-4-(2'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-mono methyl ester (2d), 2,6-dimethyl-4-(2',3'-dichlorophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-mono methyl ester (2e) and 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridin-3,5-dicarboxylic acid (2f) were obtained from the methyl iodide salts in 91-98% yield.

• 약학회지
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• 제33권5호
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• pp.280-284
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• 1989

When 2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-mono methyl ester(3) was reacted with dimethyl methylene ammonium chloride (5a) and $K_2CO_3$ in DMF, 2,6-dimethyl-4-(3'-nitrophenyl)-5-(N,N-dimethylamino)methyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (6a) was obtained in 41% yield. As the same procedure with compound (3) and the other dialkylaminomethylating reagents (5b, c, d, e), 2,6-dimethyl-4-(3'-nitrophenyl)-5-(N,N-diethylamino)methyl-1,4-dihydropyridine-3-carboxylic acid methylester(6b), 2,6-dimethyl-4-(3'-nitrophenyl)-5-(1'-pyrrolidinyl)methyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (6c), 2,6-dimethyl-4-(3'-nitrophenyl)-5-(1'-piperidinyl)methyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (6d) and 2,6-dimethyl-4-(3'-nitrophenyl)-5-(1'-morpholinyl)methyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (6e) were obtained in 28%, 49%, 48% and 18% yield respectively.

• Korean Chemical Engineering Research
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• 제56권2호
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• pp.275-280
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• 2018

Methyl ester derived from coconut oil is very interesting to study since it contains free-fatty acid with chemical structure of medium carbon chain ($C_{12}-C_{14}$), so the methyl ester obtained from its part can be a biodiesel and another partially into biokerosene. The use of heterogeneous catalysts in the production of methyl ester requires severe conditions (high pressure and high temperature), while at low temperature and atmospheric conditions, yield of methyl ester is relatively very low. By using microwave irradiation trans-esterification reaction with heterogeneous catalysts, it is expected to be much faster and can give higher yields. Therefore, we studied the production of methyl ester from coconut oil using CaO catalyst assisted by microwave. Our aim was to find a kinetic model of methyl ester production through a transesterification process from coconut oil assisted by microwave using heterogeneous CaO catalyst. The experimental apparatus consisted of a batch reactor placed in a microwave oven equipped with a condenser, stirrer and temperature controllers. Batch process was conducted at atmospheric pressure with a variation of CaO catalyst concentration (0.5; 1.0; 1.5; 2.0, 2.5%) and microwave power (100, 264 and 400 W). In general, the production process of methyl esters by heterogeneous catalyst will obtain three layers, wherein the first layer is the product of methyl ester, the second layer is glycerol and the third layer is the catalyst. The experimental results show that the yield of methyl ester increases along with the increase of microwave power, catalyst concentration and reaction time. Kinetic model of methyl ester production can be represented by the following equation: $-r_{TG}=1.7{\cdot}10^6{_e}{\frac{-43.86}{RT}}C_{TG}$.

• Environmental Engineering Research
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• 제15권3호
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• pp.129-134
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• 2010

The optimization of experimental parameters, such as catalyst type, catalyst concentration, molar ratio of alcohol to oil and reaction temperature, on the transesterification for the production of rapeseed methyl ester has been studied. The Taguchi approach (Taguchi method) was adopted as the experimental design methodology, which was adequate for understanding the effects of the control parameters and to optimize the experimental conditions from a limited number of experiments. The optimal experimental conditions obtained from this study were potassium hydroxide as the catalyst, at a concentration of 1.5 wt %, and a reaction temperature of $60^{\circ}C$. According to Taguchi method, the catalyst concentration played the most important role in the yield of rapeseed methyl ester. Finally, the yield of rapeseed methyl ester was improved to 96.7% with the by optimal conditions of the control parameters which were obtained by Taguchi method.

• 한국환경농학회지
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• 제16권3호
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• pp.269-273
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• 1997

천연의 (S)-(+)-ABA 보다 우수한 생육저해 활성을 갖는 ABA 유도체를 개발하기 위한 연구의 일환으로 p-hydroxy methyl cinnamate와 umbelliferone을 (S)-(+)-2-cis, 4-trans-ABA에 ester 결합시켜서 ABA-methyl cinnamate ester(AC)와 ABA-umbelliferone ester(AU) 화합물을 각각 83%와 78%의 높은 수율로 얻었다. 이들의 벼 유묘 생육저해 활성은 (+)-ABA에 비해서 AC가 $3{\sim}10$배, AU가 $10{\sim}30$배 정도로 훨씬 더 강한 활성을 보였다.

• 공업화학
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• 제10권1호
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• pp.135-137
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• 1999

새로운 인돌 유도체인 항염증제를 합성하기 위하여 ${\alpha}$-benzoyl-1-ethyl-1,3,4,9-tetrahydro-8-ethyl-9-(N-benzoyl)pyrano[3,4-b]indole-1-acetic acid methyl ester(10)을 합성하였다. 출발물질은 7-ethylindole과 oxalyl chloride로 하여 4단계로 이루어졌다. 셋째 단계는 borontrifluoride diethyl etherate을 사용하여 66%로 고리화반응을 하였으며, 환원반응과 고리화반응도 효율적으로 단순화하였다. 최종생성물인 ${\alpha}$-benzoyl-1-ethyl-1,3,4,9-tetrahydro-8-ethyl-9-(N-benzoyl)pyrano[3,4-b]indole-1-acetic acid methyl ester는 4단계에서 얻은 methyl 1,8-dimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetate(etodollic acid methyl ester)를 benzoyl chloride와 반응하여 66%의 수율로 얻었다.

• Tribology and Lubricants
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• 제35권2호
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• pp.132-138
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• 2019

In this study, we demonstrate the effects of the acidic properties of montmorillonite (MMT), which is commonly used as a catalyst, on the conversion and selectivity of the dimer acid methyl ester (DAME) synthesis. We synthesize DAME by the dimerization of conjugated linoleic acid methyl ester (CLAME) and oleic acid methyl ester using MMT KSF. Incidentally, trimer acid methyl ester was formed as a by-product during the DAME synthesis. There is a necessity to adequately adjust the strength and quantity of the acid site to control the selectivity of DAME. Therefore, we vary the pH of the MMT acid by using various metal hydroxides. The purpose of this study is to increase the yield of monocyclic dimer acid methyl ester, which is a substance with adequate physical properties for industrial applications (e.g., lubricant and adhesive, etc.), using a heterogeneous catalyst. We report the dimerization of fatty acid methyl ester by using base treated-KSF, and apply it to conjugated soybean oil methyl ester. Then, we transmute the acid site properties of KSF, such as pH of 5 wt.% slurry KSF and various alkali metals (Li, Na, K, Ca). Characterization of base treated-KSF using a pH meter, x-ray diffraction, inductively coupled plasma-atomic emission spectrometer, Brunauer-Emmett-Teller surface analysis, and temperature-programmed desorption. We conduct an analysis of CLAME and DAME using nuclear magnetic resonance spectroscopy, gas chromatography, and gel permeation chromatography. Through these experiments, we demonstrate the effects of the acidic properties of KSF on the conversion and selectivity of the DAME synthesis, and evaluate its industrial potential by application to waste vegetable oil.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.621-634
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• 2001

피마자유와 메탄올의 transesterification 반응 (methanolysis)에서 Novozym 435가 가장 좋은 활성을 나타냈다. Novozym 435의 경우 유기용매를 사용하지 않을 경우에도 좋은 활성을 유지하였고 사용되는 효소량에 따라 최적의 유기용매가 다르다는 것을 확인하였다. 0.5 wt% Novozym 435를 사용한 경우 DIPE를 사용하였을 매 가장 높은 활성을 나타내었으나, 1.0 wt% 의 경우에는 heptane을 이용하였을 때 가장 높은 활성을 보였다. Novozym 435를 이용한 피마자유의 methanolysis에서 methanol 에 의한 저해 반응이 나타나고 oil과 methanol의 몰 비 가 약 1:7.37 일 경우 최대의 ricinoJeic acid methyl ester 를 얻을 수 있었다. 1.0wt%의 Novozym 435를 이용한 methanolysis를 통하여 하루동안 피마자유로부터 ricinoleic acid methyl ester 를 86.1% 의 수율로 얻을 수 있었다.