• Journal of the Korean Chemical Society
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• v.20 no.6
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• pp.453-459
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• 1976

Rate constants for the reaction of methyl chloroformate with substituted anilines, and for the halogen exchanges in phenyl chloroformate have been determined in acetone. Although the rate data can be interpreted equally well with the addition-elimination mechanism($S_AN$) involving an intermediate, results of MO and isotope effect studies strongly favor the synchronous ($S_N2$) mechanism for the reactions studied. It was concluded that for the fast reacting nucleophiles the transition state is of "late" type while for the slow reacting nucleophiles it is of "early" type.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.227-231
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• 1990

Kinetic studies on the nucleophilic reactions of p-substituted benzylnitrates with substituted anilines have been conductometically carried out in 50-100% $CH_3CN-CH_3OH$ mixtures. From the kinetic data, Hammett ${\rho}_C$ and ${\rho}_N$ values, Bronsted $\beta$ values, and solvatochromic coefficients were determined in order to examine the transition state variations caused by changes in substituents and solvent properties. It is concluded that the reaction proceeds via a synchronous $S_N2$ mechanism in which bond formation is more advanced than bond cleavage.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.385-393
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• 2004

2-Ethoxycarbonyl-3-methylquinoxaline 1,4-dioxide (8) was synthesized from benzofuroxan and ethyl acetoacetate. The reaction of compound 8 with hydrazine hydrate or selenium dioxide gave 2-hydrazinocarbonyl-3-methylquinoxaline 1,4-dioxide (9) or 2-ethoxycarbonyl-3-formylquinoxaline 1,4-dioxide (10), respectively. The reaction of compound 9 with alkanoyl chlorides, benzoyl chlorides, heteroacyl chlorides, and benzenesulfonyl chlorides afforded 3-methyl-2-(substituted hydrazinocarbonyl)quinoxaline 1,4-dioxides (11-14), respectively. The reaction of compound 9 with sodium azide gave 2-azidocarbonyl-3-methylquinoxaline 1,4-dioxide (15), and then its refluxing in dioxane/alcohols resulted in the Curtius rearrangement to give N-(3-methyl-1,4-dioxoquinoxalin-2-yl)-alkyl carbamates (16). The reaction of compound 15 with substituted anilines afforded 2-(3-substituted phenylureido)-3-methylquinoxaline 1,4-dioxides (17). The reaction of compound 10 with benzoic hydrazide or substituted anilines provided quinoxaline 1,4-di-oxides (18, 19), respectively. The herbicidal and fungicidal activities of the synthesized compounds were investigated.

• Journal of the Korean Chemical Society
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• v.28 no.3
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• pp.155-162
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• 1984

Kinetic studies for the nucleophilic substitution reactions of para-substituted benzyl bromides and benzyl iodide with anilines were carried out in MeOH-MeCN mixtures at 35.0$^{\circ}$C. Hammett $ {\rho}_N,\;{\rho}_C$, Bronsted $ {\beta}$ and solvatochromic correlation coefficient a, s values were determined in order to clarify the transition state variations caused by changing nucleophiles, substituents, leaving group and solvents. The results of solvatochromic equation showed that ${\pi}^{ast}$effect was a dominant factor for the reaction systems studied. It was shown that the reaction proceeds via the dissociative $S_N$2 mechanism using the potential energy surface model approach. The potential energy surface model approach however failed to account for the transition state variation due to leaving group changes. The quatum mechanical approach showed that kinetic results were consistent with proposed dissociative $S_N$2 mechanism.

• Journal of the Korean Chemical Society
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• v.19 no.3
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• pp.156-162
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• 1975

Rates of reactions of methanesulfonyl chloride with various substituted anilines have been measured in methanol. Substituent effects in aniline are found to be linearly correlated with pKa(Bronsted relation with ${\beta}$ = 0.84) and ${\rho}$(Hammett equation with ${\rho}$ = -2.46) respectively. The results are interpreted in terms of degree of bond-formation at the transition state, which was found to have progressed relatively further. The rates for o-methylaniline deviated from the Bronsted plot established by meta and para substituted anilines because of a steric effect of ortho position in aniline. Activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$ have also been determined. The enthalpy of activation showed a regular variation in that electron donating substituents in the p-substituted aniline decrease ${\Delta}H^{\neq}$ and increase the negative value of ${\Delta}S^{\neq}$.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1703-1708
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• 2011

ZSM-5-$SO_3H$ efficiently catalyzed the one-pot three-component Mannich reaction of aldehydes, anilines, and ketones. ${\beta}$-Aminocarbonyl compounds were obtained in reasonable yields and excellent stereoselectivities when the reaction was carried out at room temperature under solvent-free conditions. Simple experimental conditions and product isolation procedure makes this protocol potential for the development of clean and environment-friendly strategy for the synthesis of ${\beta}$-amino-ketones. The catalyst was recovered and reused for subsequent runs.

• Journal of the Korean Chemical Society
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• v.58 no.2
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• pp.186-192
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• 2014

A series of novel pseudopeptides contained coumarin skeleton were synthesized through the Ugi-four-component reaction. The 3-substituted coumarin-3-carboxamides were formed through reaction of benzaldehyde derivatives, anilines, coumarin-3-carboxylic acid and isocyanides with high yields and high bond-forming efficiency at room temperature. These novel amidated coumarins exhibit brilliant fluorescence in range of 535-547 nm in chloroform.

• Applied Biological Chemistry
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• v.37 no.6
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• pp.522-525
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• 1994

Fourteen 2-(1-anilinobutylidene)-5,5-dimethyl-3-hydroxy-2-cyclohexen-1-ones were prepared by condensation of 2-butanoyl-5,5-dimethyl-3-hydroxy-2-cyclohexen-1-one with various substituted anilines in good yield. These were tested for herbicidal activity against six different submerged paddy weed species. Most compounds showed significant activity against Echinochloa crus-galli and Sagittaria pygmaea with excellent tolerance to rice.

• Journal of the Korean Applied Science and Technology
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• v.15 no.2
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• pp.49-57
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• 1998

This study is to develop a new synthetic method for the nitroarenes via non-electrophilic substitution. Direct nitration at the C-1 position of isoquinoline has never been reported and substitution in isoquinoline under the normal nitration condition occurs at C-5 and C-8. We have demonstrated a facile one-step sythetic method for the nitration of isoquinolines at the C-1 position, which involves the electrophilic attack of a $DMSO-Ac_2O$ complex, followed by nucleophilic addition of nitrate ion to this intermediate. Since the reaction is simple and mild, this method has preparative merit since 1-nitroisoquinolines are not readily accessible by other methods. Application to the synthesis of poly nitroarenes from the corresponding anilines was also described.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2357-2360
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• 2010

Kinetic studies on the pyridinolysis of aryl dithiocyclopentanecarboxyaltes 2 were carried out at $60.0^{\circ}C$ in acetonitrile. In the aminolysis of 2, the $\beta_X$ values were 0.5 - 0.8 with anilines, and there was no breakpoint. However, in the pyridinolysis of 2, biphasic Bronsted plots were obtained, with a change in slope from a large value ($\beta_X{\cong}0.7$) to a small value ($\beta_X{\cong}0.4$) at $pK_{a}^0$ = 5.2. This was attributed to a change in the rate-limiting step from breakdown to the formation of a zwitterionic tetrahedral intermediate, $T^{\pm}$, in the reaction path, with an increase in the basicity of the pyridine nucleophile. An obvious change in the cross-interaction constant ${\rho}_{XZ}$ from a large positive ($\rho_{XZ}$ = +1.02) value to a small negative value (${\rho}_{XZ}$ = -0.17) supports the proposed mechanistic change.