• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1887-1890
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• 2010

Cross-linked polystyrene supported aluminium triflate (Ps-Al(OTf)$_3$) was found to be an efficient and chemoselective heterogeneous Lewis acid catalyst for the direct conversion of arenes to sulfones using sulfonic acids as sulfonylating agents. The solid acid catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency.

• Journal of the Korean Applied Science and Technology
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• v.6 no.2
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• pp.21-28
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• 1989

1-naphthol-2-sulfonic acid and 1-naphthol-4-sulfonic acid were synthesized under the dissolution of 1-naphthol in 2-nitrotoluene with stirring 98.08-90％ sulfuric acid at $5-95^{\circ}C$ for 1-5 hours. As the reaction temperatures and the reaction time were raised, the yield of 2-sulfonate was decreased, while that of 4-sulfonate was increased. But we could not observe the tendency to the various reaction concentrations of sulfuric acids. The mixtures of two isomeric 1-naphtholulfonic acids in excess concentrated sulfuric acids was quantitatively determinded by using multicomponent spectrophotomeric analysis method on the basis of the ultraviolet absorption peak of the sulfonic acids. The standard deviation in this method was ${\pm}\;2.6$, and the above method seem to be rapid and accurate.

• Journal of the Korean Applied Science and Technology
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• v.3 no.2
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• pp.29-34
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• 1986

The sulfuric acid sulfonation of 2-aminonaphthalene was preformed at $30^{\circ}C{\sim}200^{\circ}C$ for $1{\sim}15$ hours, using $4{\sim}10$ parts of 90% sulfuric acid${\sim}$20% oleum. This reaction was influenced by many factory such as reaction temperature, reaction time, strength of sulfuric acid and amount of sulfuric acid and among these factors, the effect of the reaction temperature was considerable. The main products of this reaction were Dahl's acid (2-aminonaphthalene-5-sulfonic acid, Broenner's-acid (2-aminonaphthalene-6-sulfonic acid), amnio-F-acid(2-aminonapthalene-7-sulfonic acid), and Baden acid (2-aminonaphthalene-7-sulfonic acid) and another isomers such as Tobia's acid (2-aminonaphthalene-1-sulfonic acid) and 2-aminonaphthalene-4-sulfonic acid were not formed. Of these isomeric acids, those containing the sulfonic acid group in an ${\alpha}-position$, namely, Dahl's acid and Baden acid, are simultaneously formed by sulfonation at low-temperature ($30{\sim}100^{\circ}C$), whilst those containing the sulfonic acid group in a ${\beta}$-position, namely, Broenner's acid and amino-F-acid, are formed simultaneously by sulfonation at high temperatures($150^{\circ}{\sim}200^{\circ}$).

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.18-27
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• 2002

Pine bark was liquefied in the presence of phenol using organic sulfonic acids as catalysts, and the liquefied barks were characterized. It was found that the organic sulfonic acids were more effective catalysts than hydrochloric acid for complete liquefaction of pine bark. The liquefied barks prepared from phenol-organic sulfonic acid liquefaction were highly phenolated, and the amounts of combined phenol were 2-3 times greater than that of the liquefied bark obtained from phenol-hydrochloric acid liquefaction. The glass transition points (Tg) were lower than that of the liquefied barks prepared from phenol-hydrochloric acid. It can be concluded that by using the organic sulfonic acids, the phenol used as a liquefying reagent is highly introduced into the bark, resulting in the phenolated bark preventing further condensation reactions, which may occur during the liquefaction. The carbohydrates such as cellulose and hemicellulose in the liquefied barks were almost decomposed during the liquefaction, from the results of IR spectra and neutral sugar analyses. Energy dispersive X-ray spectromery (EDS) results from the residues and the liquefied barks showed that the organic sulfonic acid catalysts did not lead to serious corrosion of the reactor compared with the hydrochloric acid catalyst.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.1-9
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• 2002

Various types of acids, such as mineral acids, organic acids, and organic sulfonic acids, were used as catalysts in order to investigate their effectiveness during phenol liquefaction of pine bark. Hydrochloric arid was the most effective acid catalyst of the mineral acids used in this experiment for the phenol liquefaction, but the amount of the acid needed for more than 90% liquefaction was at least 11 mmol. Among the carboxylic acids used triflouroacetic acid (TFA) was effective for the liquefaction, but it was not possible to obtain liquefaction of more than 80%. Organic sulfonic acids, p-toluenesulfonic acid (PTSA) and methanesulfonic acid (MSA), showed remarkable effects for liquefaction, even in small amounts and at low liquefaction temperatures. Especially in the case of PTSA, a 92% liquefaction yield was obtained at the liquefaction condition of 14$0^{\circ}C$ for 2 h. Therefore, it was evident that the PTSA is a good acid catalyst for the phenol-pine bark liquefaction system.

• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.224-230
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• 1986

Dodecyltrimethylammonium bromide (DTAB) was examined as a counter-ion in the separation of aromatic sulfonic acids on alkylmodified silica (ODS) column by reversed-phase ion-pair chromatography. The capacity factor of acids was investigated and separation was attempted. The capacity factor of samples was influenced by the several factors such as a concentration of counter-ion, concentration of methanol, kinds and concentration of electrolyte in mobile phase as well as kinds and position of functional group in samples. Some mixtures of samples were able to be separated under optimum condition.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.38-41
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• 1961

By varying groups on biologically active molecules, it is possible to produce analogues which sometimes inhibit the action of the parent compound. Such is true of taurine(${\beta}$-amino-ethane sulfonic acid)as an analogue of ${\beta}$-alanine and of pantoyl taurine for pantothenic acid. It seemed possible that the sulfonic acid analogues of amino acids built into peptides might possibly produce inhibition of the parent peptide. Tauryl-L-histidine was selected to prepare as an analogue of carnosine(${\beta}$-alanyl-L-histidine). There were several reasons for this choice. Camosine causes a slight contraction of isolated uterine muscle and inhibition of this action can be easily tested. Also, taurine, being a ${\beta}$-amino sulfonic acid, is much more stable than the ${\beta}$-amino sulfonic acids. Phthalyl tauryl-L-histidine methyl ester was prepared by condensing phthalyl tauryl chloride with histidine methyl ester in chloroform. The yields were quite low possibly due to reaction between the acid chloride and the imidazole of histidine. Approximately 50 per cent yield of crude amorphous product was obtained, but upon purification by crystallization they yielded only 25 percent of a pure product. The methyl ester was removed by acid hydrolysis to prevent partial cleavage of the phthalyl group. Crystalline tauryl histidine was then obtained from this acid by removal of the phthalyl group by hydrazinolysis. Tests for inhibition were carried out by comparing the action of camosine on isolated uterine muscle before and after tauryl histidine had been added to the bath surrounding the muscle strip. Only in very high relative concentrations of tauryl histidine was there any demonstrable inhibition.

• Journal of the Korean Chemical Society
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• v.37 no.9
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• pp.793-799
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• 1993

Ion-pair model was predominated over ion-interaction model in the retention mechanism of analytes when tetramethylammonium bromide (TMAB) was used as a counter-ion in the investigation of aromatic sulfonic acids on the reversed-phase liquid chromatography by $C_{18}$ column as a stationary phase. The capacity factors of analytes were influenced by the type and concentration of counter-ions, concentrations of methanol and co-anion, types and position of functional group, and the pH mobile phase. Components of analyte mixture could be separated under the optimum conditions by this method.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.984-988
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• 2010

1-(Fluoren-2-yl)-benzo[d][1,2,3]triazoles 5a-b were synthesized starting from 2-nitrofluorene. 2-Nitrofluorenes 1a-b were reduced by catalytic hydrogenation, reacted with 2,4-dinitrofluorobenzene followed by catalytic hydrogenation to afford 2-(N-2,4-diaminophenyl)aminofluorenes 4a-b. Diazotization of 4a-b with $NaNO_2/H_2SO_4$ followed by treatment with $H_3PO_2$ gave 5a-b. Sulfonation of 5a-b yielded 7-benzotriazol-1-yl-fluorene-2-sulfonic acids 6a-b. The structures of 5b and 6b were firmly identified by X-ray crystal analysis in addition to $^1H$ NMR, $^{13}C$ NMR, and elemental analysis.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2701-2706
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• 2009

The polymer blends containing polypyrrole (PPy) and the sulphonic acids such as β-naphthalene sulfonic acid (NSA), camphor sulfonic acid (CSA), and dodecylbenzenesulfonic acid (DBSA) were synthesized by in situ deposition technique in an aqueous media using ammonium per sulfate (APS) as an initiator. The obtained films were characterized by scanning electron microscopy (SEM), and the thermal behavior of these polymer blends was analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The temperature-dependent (DC) conductivity of the obtained films shows a semiconducting behavior with a negative temperature coefficient of resistivity (TCR). The conductivity data were also analyzed through Mott’s equation, which provides the variable range hopping model in three dimensions. The parameters such as density of states at the Fermi energy, hopping energy, and hopping distance were calculated for PPy, PPy-NSA, PPy-CSA, and PPy-DBSA films, and the data were compared.