• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3895-3898
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• 2012

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.1064-1066
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• 2010

• Natural Product Sciences
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• v.17 no.1
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• pp.1-4
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• 2011

Chemical investigations of the stony coral Alveopora japonica Eguchi (Poritidae) resulted in the isolation of four known compounds (1 - 4). The structures of 1 - 4 were identified as a sterol, ergosta-5,24(28)-dien-$3{\beta}$-ol (1), a mixture of monoacyl glycrols (2), eicosanoic acid and tetracosanoic acid, and two nucleosides, thymine (3) and 2'-deoxythymidine (4), respectively, on the basis of spectroscopic and physicochemical analyses including 1D- and 2D- NMR techniques as well as by comparison of their data with the published values. Compounds 1 - 4 were isolated from this species for the first time. Moreover, these compounds (1 - 4) were found in the genus Alveopora and the family Poritidae for the first time.

• Journal of the Korean Chemical Society
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• v.8 no.4
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• pp.135-141
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• 1964

The reaction of potassium fluoride with amyl iodide in presence of dimethylformamide at low temperature gave a fluorination product together with decane. Polyhalogenated acid such as ${\alpha}$, ${\beta}$,-dichloro-${\beta}$-phenyl-propionic acid gave ${\alpha}$-chlorostyrene, fluorinated styrene, and fluorinated acid. The same reaction with the ethyl ester did not give the fluorination product and gave a mixture of various dimerized product. Dibromostyrene gave bromostyrene together with fluorination product. Iodo acid such as m-iodo acid gave the salt and a trace quantity of dimerized product. Iodides such as m-iodotoluene and 1-amino-4-iodo-2-methyl benzene did not show any appreciable reactivity towards potassim fluoride. The reaction condition was described, and fluorination, ${\alpa}$-dehydrofluorination, decarboxylation, and dimerization were discussed.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.589-593
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• 2010

TBACl (10 mol %) was found to be a useful catalyst for the synthesis of substituted benzimidazoles. The method was proved to be simple, convenient and the product was isolated with good yield.

• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1632-1636
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• 2003

Palladium-catalyzed cross-coupling reactions of neopentyloxysulfonylphenyl bromides with arylboronic acids provided a variety of neopentyl biphenylsulfonates in good yields. 2-Bromo- and 4-bromobenzenesulfonates underwent the coupling reaction more rapidly than 3-bromobenzenesulfonate, while chlorobenzenesulfonate did not produce the coupling product under the standard reaction conditions.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.47-47
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• 2000

• Carbon letters
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• v.25
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• pp.95-102
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• 2018

We examined the pressure effects on petroleum pitch synthesis by using open and closed reaction systems. The pressure effects that occur during the pitch synthesis were investigated in three pressure systems: a closed system of high pressure and two open systems under either an atmosphere or vacuum. A thermal reaction in the closed system led to the high product yield of a pitch by suppressing the release of light components in pyrolysis fuel oil. Atmospheric treatment mainly enhanced the polymerization degree of the pitch via condensation and a polymerization reaction. Vacuum treatment results in a softening point increase due to the removal of components with low molecular weights. To utilize such characteristic effects of system pressure during pitch preparations, we proposed a method for synthesizing cost-competitive pitch precursors for carbon materials. The first step is to increase product yield by using a closed system; the second step is to increase the degree of polymerization toward the desired molecular distribution, followed by the use of vacuum treatment to adjust softening points. Thus, we obtained an experimental quinoline insolubles-free pitch of product yield over 45% with softening points of approximately $130^{\circ}C$. The proposed method shows the possibility to prepare cost-competitive pitch precursors for carbon materials by enhancing product yield and other properties.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.4
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• pp.7-14
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• 2001

Recycled fibers usually give slow drainage in the paper forming process, which limits the application of more refining to the recycled fibers for improving paper strength and formation. To use recycled fibers more effectively, especially OCC, developing very efficient handling technique of short fibers and fines is inevitable. We tried to make hard flocs of fractionated short fibers and fines, which were the main cause of slow drainage, by adding excessive amount of retention aid selectively on them. This technique was proved to increase drainage considerably, but to decrease strength properties, compared to the conventional technique of adding the same amount of polymers to the whole furnish in the lab test. The bonding capability of short fibers and fines in Korean OCC was very poor. Various chemical treatment on the short fibers and fines of the Korean OCC did not improve their bonding and optical properties. One of the reasons of no improvement in their properties was their high amount of ashes.

• Journal of the Korean Chemical Society
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• v.21 no.3
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• pp.180-186
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• 1977

The preparation of 1-chloro-2-iodoperfluorocycloalkenes was achieved with a short reaction time and a high yield when the starting compound was iodinated via the metalation process using an alkyllithium reagent. Especially, the high yield of 1-chloro-2-iodo-perfluorocyclohexene was obtained when 1,2-dichloroperfluorocyclohexene was iodinated via the same reaction conditions. The coupling reaction of 1,2-dihaloperfluorocycloalkenes was also achieved with a lower reaction temperature and a shorter reaction time when the equal slurry mixture of fluorocycloolefines and DMF was reacted at a high pressure in a sublimer. The yield of the coupling product was greatly improved by this process. For a typical example, the coupling reaction of the 1-chloro-2-iodotetrafluorocyclobutene was proceeded with a higher yield of the product than that of the reported reaction, when the present method was adopted. A plausible reaction mechanism of the present coupling reactiont was proposed and the physical characteristics of the coupling product were confirmed.