• Journal of the Korean Chemical Society
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• v.13 no.3
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• pp.215-219
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• 1969

The kinetics of the reaction of m-or p-substituted benzyl bromides with thiourea in methanol at 35.0$^{\circ}$were determined by an electric conductivity method. According to a plot of log k against the Hammett substituent constants, C-Br bond cleavage in benzyl bromide is postulated to be a rate determining step at the SN2 reaction of benzyl bromide with thiourea. Both electron-donating substituents and electron-withdrawing substituents quantitatively affected the rate of reaction, but each in a different manner. A mechanistic possibility was proposed to account for the results. Some activation parameters were also calculated.

• Journal of the Korean Chemical Society
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• v.9 no.3
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• pp.148-151
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• 1965

Kinetics of reactions of chloride and bromide ions with benzyl chloride and bromide have been investigated in 90% ethanol solution. Semi-quantitative analysis of the results shows that the bond-formation is more important than the bond-breaking and furthermore in bond-formation the energy gain due to bond-formation is less than the increase in electron affinity of the nucleophile.

• Journal of the Korean Chemical Society
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• v.39 no.8
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• pp.643-649
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• 1995

The Menschutkin type reactions of substituted(Z)-benzyl systems with substituted(Y)-pyridines and N,N-dimethyl aniline have been studied by the electro-conductometric method in acetonitrile at 35$^{\circ}C$ and 50$^{\circ}C$. On the plot of $k_{obs}$ versus concentrations of nucleophile under pseudo-first order conditions, 3,$4-(CH_3/O)_2$-benzyl bromide and $4-CH_3O$-benzyl bromide were a positive intercept at zero concentration of nucleophile. The $k_1$ value for each compound was invariant with the different nucleoephile. However, $4-CH_3-$ and other electron withdrawing substituents of benzyl bromides did not show the positive intercept. These results are suggested that the reactions have been proceeding simultaneously and independently for the activated benzyl bromides via direct bimolecular and intimate ion pair intermediate.

• Bulletin of the Korean Chemical Society
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• v.13 no.4
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• pp.391-395
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• 1992

Rhodium(I) and iridium(II) complexes, M(Cl$O_4$)(CO)$(PPh_3)_2$ and [M(CO)$(PPh_3)_3$]Cl$O_4$ (M = Rh, Ir), and RhX(CO)$(PPh_3)_2$ (X = Cl, Br, OH) catalyze the carbonylation of benzyl alcohols to produce phenylacetic acids under 6 atm of CO at $110^{\circ}C$ in deuterated chloroform. Benzyl alcohols initially undergo dehydration to give dibenzyl ethers which are then carbonylated to benzyl phenylacetates, and the hydrolysis of benzyl phenylacetate produces phenylacetic acids and benzyl alcohols. The carbonylation is accompanied with dehydrogenation followed by hydrogenolysis of benzyl alcohols giving benzaldehydes and methylbenzenes which are also produced by CO2 elimination of phenylacetic acids. Phenylacetic acid is also produced in the reactions of benzyl bromide with CO catalytically in the presence of Rh(Cl$O_4$)(CO)$(PPh_3)_2$ and $H_2O$, and stoichiometrically with Rh(OH)(CO)$(PPh_3)_2$ in the absence of $H_2O$.

• Macromolecular Research
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• v.16 no.3
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• pp.238-246
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• 2008

A new strategy using protection-deprotection chemistry was used to prepare branched polymers using the ATRP method only. Among the several monomers with different protecting groups, vinyl benzyl t-butyloxy carbonate (VBt-BOC) and 4-methyl styrene (4-MeSt) could be polymerized successfully to form backbones using the ATRP method in a controlled fashion. The protected groups in the backbones were converted to alkyl bromides and used as initiating sites for branch formation. The benzyl t-butyloxy carbonate groups in the backbones containing VBt-BOC units were first deprotected to benzyl alcohol by trifluoroacetic acid, then converted to benzyl bromide by reacting them with triphenylphosphine/carbon tetrabromide. The benzyl bromide groups in the backbones containing 4-MeSt units could be generated by bromination of the methyl groups using N-bromosuccinimide/benzoyl peroxide. The structures of the prepared polymers were well-controlled, as evidenced by the controlled molecular weight as well as the narrow and unimodal molecular weight distribution.

• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1491-1492
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• 2005

• Bulletin of the Korean Chemical Society
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• v.3 no.2
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• pp.55-60
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• 1982

The rate of the bromine-exchange reaction of antimony tribromide with benzyl bromide in nitrobenzene or 1,2,4-trichlorobenzene has been measured, using Br-82 labelled antimony tribromide. The result of the study indicates that the exchange reaction is first order with respect to benzyl bromide, and either second or first order with respect to antimony tribromide depending on its concentrations. The second-order kinetics with respect to antimony tribromide have been observed at relatively high $[SbBr_3]$ concentrations, and the first-order kinetics at lower $[SbBr_3]$ concentrations. Reaction mechanisms are proposed for the exchange reaction.

• Korean Journal of Food Science and Technology
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• v.12 no.1
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• pp.41-44
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• 1980

The model compounds of Vitamin $B_1$ 3-benzyl-4-methylthiazolium bromide, (1), 3, 4-dimethylthiazolium iodide (2) and 2-($\alpha$-hydroxyethyl)-3-benzyl-4-methylthiazolium bromide (3) were prepared by the organic synthesis. Colorimetric determination with phosphotungstic acid showed an increase of $1.1{\sim}1.2$ folds with compound (1) and $1.5{\sim}1.9$ folds with compound (3) when readings were carried out after an overnight, compared with immediate readings. Colorimetry with 2.6-dibromoquinone chloroimide yielded the compound (1) being $2.2{\sim}2.5$ folds higher than the compound (3). The half wave potentials and diffusion currents of anodic and cathodic waves of polarography with the same concentration of the compounds (1), (2) and (3) also resulted in different values of their waves. Therefore, it was a firm conclusion that any values obtained from quantitative analysis with this model compounds (1), (2) and (3) were not directly applicable to those of $B_1$.

• Applied Biological Chemistry
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• v.37 no.3
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• pp.189-193
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• 1994

The hydrolysis of fungicidal N-[1-(benzotriazol-1-yl)benzyl]aniline (BBA) molecule in the presence of cationic cetyltrimethylammonium bromide (CTABr) and anionic sodium laurylsulfate (NaLs) micellar solutions has been studied kinetically. The Micellar catalysis effect shows that the rate is slightly accelerated by the addition of the anionic NaLs at high pH and the binding constant (Ks) is $1.45{\times}10^4M^{-1}$. This result presumably is due to the electrostatic stabilization by the anionic micelle of the developing carbocation in the transition state rather than the hydrophobic character (${\pi}$: 4.93) of (BBA).

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.70-77
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• 1991

1-Benzyl-4-iodomethyl-2-azetidinone(BIMA) was synthesized and its electrochemical reduction was investigated by direct current, differential pulse polarography, cyclic voltammetry and controlled potential coulometry. The irreversible two electron transfer on reductive dehalogenation of iodo group proceeded to form 1-benzyl-4-methyl-2-azetidinone by EEC electrode reaction mechanism at the first reduction step(-1.35 volts vs. Ag-AgCl). The polarographic reduction waves separated into two reduction steps due to anionic surfactant (sodium lauryl sulfate) effects, while the waves were shifted to the positive potential as the concentration of cationic surfactant (cetyltrimethylammonium bromide) increased. Upon the basis of results on the product analysis and interpretation of polarogram with pH variable, EEC electrochemical reaction mechanism was suggested.