• Analytical Science and Technology
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• v.14 no.1
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• pp.1-7
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• 2001

6,6-Dichlorobicyclo[3, 1, 0]hexane-3carboxylic acid was synthesized by dichlorocarbene addition into 3-cyclopentenecarboxylic acid using BTEA.Cl as phase transfer catalyst. $^1H$ NMR $^{13}C$ NMR data analyst showed that this compound had boat-like conformation and carboxyl group existed as trans form.

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.407-411
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• 1992

The effects of phase transfer catalyst was studied on the substitution of CO ligand of $Mo(CO)_6$ [M=Cr, Mo, W] with two electron-pairs donating ligands, 2, 2'-bipyridine and 2, 2'-biquinoline. The change of product yield, $M(CO)_4(L)_2$, was discussed according to reaction time, mole composition of $M(CO)_6$, and type of ligand.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.274-279
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• 1992

Immobilization method of lariat azacrown ethers, containing hydroxyl group in the side arm of crown ring, on the polymer matrix and the phase-transfer catalytic activity of thus obtained immobilized lariat azacrown ethers were studied. Polystyrene resins with crown ether structures and hydroxyl groups adjacent to the macrorings were prepared by the reaction of crosslinked polystyrene resins containing epoxy groups with monoaza-15-crown-5 or monoaza-18-crown-6. Microporous crosslinked polystyrene resins containing epoxy group for the syntheses of these immobilized lariat crown catalysts were prepared by suspension polymerization of styrene, divinylbenzene (DVB 2%) and vinylbenzylglycidyl ether. The immobilized lariat catalysts with 10-20% ring substitution exhibited maximal activity for the halogen exchange reactions of 1-bromooctane with aqueous KI or NaI under triphase heterogeneous conditions. Immobilized catalyst exhibited higher activity than corresponding catalyst without the hydroxyl group and this result was suggested that the active site have a structure in which the $K^+$ ion was bound by the cooperative coordination of the crown ring donors and the hydroxyl group in the side arm.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.744-748
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• 2010

2,3,4,5-Tetrafluorobenzoic acid, an important intermediates of fluoroquinolone antibiotics, was synthesized from tetrachloride phthalic anhydride through imidation, fluorination, hydrolysis and decarboxylation. The effects of phase transfer catalyst on imidation and fluorination reaction and the effects of surfactants on the hydrolysis reaction were studied, respectively. Experimental results showed that the imidation reaction time was greatly reduced in the presence of a phase transfer catalyst, hexadecyltrimethyl, resulting in imidation yield as high as 98.2%. The fluorination yield reached 81.3% when tetrabutylammonium bromide was chosen as a phase transfer catalyst. The hydrolysis reaction time was also decreased by adding hexadecyltrimethyl while increasing the yield to 88.6%. In the post-processing, the sublimation method was used to purify the product, and ideal effect was obtained. In the decarboxylation reaction, tetrafluoride phthalic acid was obtained by decarboxylation in the solvent of tri-n-butyl amine and decarboxylation yield reached 81.6%. Compared with the literature method, the overall reaction time of the improved method decreased from 53 h to 20.5 h and the total yield increased from 47.3% to 57.4%.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.74-80
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• 1994

Synthesis of benzophenone by oxidation of diphenylmethane at room temperature is studied using Aliquat 336 as phase transfer catalyst and potassium tert-butoxide as base. No other study has shown that diphenylmethane can be oxidized to benzophenone with quaternary ammonium salt as phase transfer catalyst. However, in presence of Aliquat 336, higher than 30% of benzophenone was yielded. The conversion of diphenylmethane was increased with increasing amount of Aliquat 336 and Potassium tert-butoxide. Higher partial pressure of oxygen favored conversion of diphenylmethane and selectivity of benzophenone by increasing the concentration of oxygen in organic solvent A reaction mechanism involving the role of Aliquat 336 was also proposed.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.669-675
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• 2008

Carbon black has been widely used in composites, tonor resin, and ink materials. Since carbon black readily agglomerates, it is important to disperse carbon black in real applications. Aiming to improve dispersion stability, carbon black was chemically oxidized to possess hydroxyl groups using a phase transfer catalyst at room temperature. The modified carbon black (CB-OH) was grafted by a silane coupling agent, p-methylacryloxypropyltrimethoxysilane, to carry teminal vinyl groups. The modified carbon black was subsequently used in miniemulsion polymerization to achieve encapsulted core-shell structure. Finally, well-encapsulated carbon black by polymer was obtained in the size range of 100-500 nm. Throughout the polymerization, the effects of surface modification, types of monomers, initiators, and emulsifiers were investigated.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.40-40
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• 1993

2-Benzoyloxyacetophenones were prepared by reaction of benzooic acids and 2-hydroxyacetophenones in the presence of dicyclohexylcarbodiimide and 4-dimethylaminopyridine. The rearrangement of 2-Benzoyloxy acetophenones to 2-Dibenzoylmethans has been carried out in the presence of tetrabutylammoniumfl uoride( a phase transfer catalyst ). Both methods have been applied first for the synthesis of flavones and gave better yields of products and the reaction ran in shorter reaction time.

• Journal of the Korean Chemical Society
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• v.32 no.6
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• pp.593-602
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• 1988

Polymer-supported crown ethers (Ps-CE) which can be used for phase-transfer catalyst (PTC) were synthesized for the purpose of allowing reusable function to ordinary crown ethers, and the kinetics of the liquid-solid-liquid triphase-catalyzed nucleophilic displacement reaction of iodide (aqueous phase) on 1-bromooctane (organic phase) using synthesized Ps-CE (solid) were studied. Ps-CE were obtained by grafting of hydroxymethyl crown ethers to 1~2% cross-linked chloromethylated polystyrene. All reactions followed a pseudo-first order dependency on the 1-bromooctane concentration and the observed rate constants $(k_{obsd})$ were linearly related to the molar equivalents of Ps-CE, and were subjected to the influence of cross-linking density of polymer backbone, solvent and the reaction temperature. The catalytic activity of Ps-CE was also compared with that of structurally similar soluble crown ethers, and used Ps-CE were easily recovered after the reaction by simple filtration and could be reused without loss of catalytic activity in the same anionic displacement reaction. Enthalpies and entropies of activation associated with the displacement were 10~20kcal $mol^{-1}, 20~55eu. respectively, and the free energy of activation was ~30kcal mol^{-1}$.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.437-442
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• 2010

Sodium hydrogen sulphate ($NaHSO_4$), n-tetra butyl ammonium bromide (TBAB) as a phase transfer catalyst (PTC) in water, and 1-butyl-3-methyl imidazolium hydrogen sulphate [bmim]$HSO_4$ as ionic liquid (IL) has been used as a mild reaction promoter for the cyclocondensation of formalin, ${\beta}$-naphthol and aromatic amines to afford respective 2,3-dihydro-2-phenyl-1H-naphtho-[1,2-e] [1,3] oxazine derivatives. The present protocols are greener, high yielding and involved the nonchromatographic isolation procedure.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.429-436
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• 2010

A series of some biologically active halogenopurines were synthesized from commercially available guanine (1). The reaction of guanine with acetic anhydride yielded 2,9-diacetylguanine (2-1) by acetylation reaction. Further treatment of 2-1 with $POCl_3$ by PEG-2000 phase transfer catalysis furnished the important compound 3a, then 2-amino-6-halogenopurines (3b-d) were obtained through chlorine-exchange halogenations between KX and 3a by TPPB phase transfer catalyst. Further, 2-halogenopurines (2-2a-d, 4-2a-d, 5a-d) were efficiently prepared from 2-amino-6-substituted purines (1, 3a, 4-1) via a diazotization catalyzed by their corresponding CuX, and some new compounds 2-2a, 2-2c, 2-2d, 4-2c, 4-2d, 5b, 5c and 5d have been discovered. The structures of synthesized compounds were mainly established on the basis of their elemental analysis, $^1H$ NMR, as well as their mass spectral data. All the title compounds were screened for their antifungal activities, and some of the compounds showed promising activity.