• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1767-1770
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• 2009

The Henry (nitroaldol) reaction proceeds under mild conditions with catalytic amount of tetramethylethylenediamine (TMEDA) to afford $\beta$-nitro alkanol in considerably excellent yield. Structurally diverse aldehydes react with nitromethane in presence of 0.3 equiv of TMEDA under solvent-free condition at rt. The low catalytic loading and mild reaction condition are the key features of the catalytic method.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1071-1076
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• 2009

N,N,N′,N′-tetramethylethylenediamine (TMEDA) acts as a simple, mild and efficient catalyst for the acylation of alcohols, phenols and thiols at room temperature under solvent-free condition. Acylation reaction with acetic anhydride and benzoic anhydride proceeds with good to excellent yield in the presence of TMEDA as the catalyst.

• 한국기계가공학회지
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• 제10권2호
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• pp.67-72
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• 2011

Solvent-free paint is sprayed from higher-pressure conditions, because the viscosity is large. The hydraulic actuator which can be operated under higher-pressure condition is required to spray solvent-free paints in painting process for the environmental protection. The purpose of this paper is to develop the hydraulic actuator under higher-pressure conditions for solvent-free paint spraying system. The hydraulic actuator consists of inner spool, outer spool and ball. The analysis of a structural stability was conducted by using ANSYS V11 under the design condition of upward and downward movement of spool. As a result, the maximum von-Mises stress applied on spool under 4mm displacement showed a value of 106MPa which was greater than the allowable stress of the spool with a value of 250MPa and a value of safety factor 3. This result suggested that the spool system be unstable under the design condition so that it was necessary for the spool system to be reinforced to secure the structural stability.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1833-1835
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• 2005

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.744-746
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• 2006

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3963-3966
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• 2011

A series of pyranopyrazoles, was efficiently synthesized via one-pot, four component reaction of ethyl acetoacetate, hydrazine hydrate, aldehydes and malononitrile in the presence of catalytic amount silicotungstic acid under solvent free condition. NOE experiments confirmed that the product exist exclusively in the 2H form. The present protocol offers the advantages of clean reaction, short reaction time, high yield, easy purification and economic availability of the catalyst.

• 대한화학회지
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• 제55권3호
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• pp.486-489
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• 2011

Potassium dihydrogen phosphate는 마이크로파 조사조건에서 용매 없이 페놀과 아세토아세트산 에틸의 Pechmann 축합반응에 의하여 쿠마린을 합성하는 효과적인 촉매로 밝혀졌다. 이 방법은 쿠마린 합성에 있어서 소량의 촉매를 필요로 하며 수율이 높고, 반응이 깨끗할 뿐만 아니라 반응 시간이 짧은 장점들을 가지고 있다.

• 대한화학회지
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• 제55권6호
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• pp.936-939
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• 2011

Thiamine hydrochloride (VB1) has been used as an acid catalyst in organic synthesis. One pot three component Biginelli condensation of dimedone, urea/thiourea and substituted aromatic aldehydes catalyzed by 10 mol % of thiamine hydrochloride (VB1) in solvent free condition under microwave irradiation in good to excellent yields has been investigated. Utilization of microwave irradiation, simple reaction conditions, short reaction time, ease of product isolation, and purification makes this manipulation very interesting from an economic and environmental perspective.

• 대한화학회지
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• 제54권6호
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• pp.723-726
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• 2010

마이크로 반응을 이용하여 $NaHSO_4/SiO_2$을 촉매로 하는 solvent-free 합성을 통하여 $\beta$-enaminone 과 2-methylquinolin-4(1H)-one 및 그 유도체를 합성하는 효율적인 방법을 개발하였다. 반응 시간이 짧고, 수율이 좋았으며, 마이크로웨이브를 사용하지 않는 반응보다는 높은 선택성, 간단성, 무용매 반응 및 친환경적인 반응이다.

• 한국응용과학기술학회지
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• 제16권1호
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• pp.83-94
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• 1999

Glycoside fatty acid esters were synthesized by lipase-catalyzed glycosylation of fatty acids with methyl glycoside in solvent and solvent free process. Optimum condition of solvent process using 2-methyl-2-propanol were : moral ratio of methyl glycoside to fatty acid 1:3: initial concentration of methyl glycoside 50g/l:enzyme(immodilized lipase Novozym 435 from Candidia antarctica) content 1%(w/v) : desiccant content 9%(w/v); reaction temperature $60^{\circ}C$: reaction time 10hrs. The yield of 99% was obtained. Solvent-free process was carried out in total absence of solvent at $70^{\circ}C$ under reduced pressure, 5-20mmHg. To give meximum yield of 99% at the optimum condition of molar ratio of methyl glycoside to fatty acid 1:3, enzyme content 10%(w/w), and reaction time 10hrs. The glycosylation reactivity of different glycosylation agents were sequent to $Methyl-{\beta}-D-fructofuranoside$. $Methyl-{\beta}-D-glucopyranoside$. $Methyl-{\beta}-D-fructofuranosi$ de, and $Methyl-{\alpha}-D-glucopyranoside$.