• 대한화학회지
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• 제39권5호
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• pp.408-413
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• 1995

A few t-amine substituted anilines and amides were synthesized and cyclized to pyrrolo[1,2-a]benzimidazole by heating in various solvents having different polarity. Subsequent nitration of cyclized compound followed by reduction and oxidation of resulting amine afforded quinone such as 7 in 14% yield. The formation of imidazole moiety by thermal cyclization was independent on the solvent polarity. The regiochemistry for the nitration of 4 was unambiguously determined by chemical transformation.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3811-3816
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• 2013

Nucleophilic substitution reactions of ethyl methyl (2), ethyl propyl (4) and diisopropyl (7) chlorothiophosphates with substituted anilines and deuterated anilines are investigated kinetically in acetonitrile at $55.0^{\circ}C$. A concerted mechanism is proposed based on the selectivity parameters. The deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are secondary inverse ($k_H/k_D=0.66-0.99$) with 2, primary normal and secondary inverse ($k_H/k_D=0.78-1.19$) with 4, and primary normal ($k_H/k_D=1.06-1.21$) with 7. The primary normal and secondary inverse DKIEs are rationalized by frontside attack involving hydrogen bonded, four-center-type transition state, and backside attack involving in-line-type transition state, respectively. The anilinolyses of ten chlorothiophosphates are examined based on the reactivity, steric effect of the two ligands, thio effect, reaction mechanism, DKIE and activation parameter.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3245-3250
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• 2011

The nucleophilic substitution reactions of diisopropyl chlorophosphate (3) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The anilinolysis rate of 3 is rather slow to be rationalized by the conventional stereoelectronic effects. The obtained deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are secondary inverse ($k_H/k_D$ = 0.71-0.95) with maximum magnitude at X = H.A concerted mechanism involving predominant backside nucleophilic attack is proposed on the basis of the secondary inverse DKIEs.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4403-4407
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• 2011

The nucleophilic substitution reactions of dipropyl chlorothiophosphate (3) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The obtained deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are primary normal ($k_H/k_D$ = 1.11-1.35). A concerted mechanism involving predominant frontside nucleophilic attack is proposed on the basis of the primary normal DKIEs and selectivity parameters. Hydrogen bonded, four-center-type transition state is proposed. The steric effects of the two ligands on the anilinolysis rates of various substrates are discussed.

• 대한화학회지
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• 제22권1호
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• pp.7-11
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• 1978

이니트로요오도벤젠과 파라치환체 아닐린과의 반응을 아세토니트릴-메탄올 혼합용매에서 연구하였다. 행해진 반응에서의 반응속도 상수는 메탄올 용매하에서 아세토니트릴 용매에 비해 큰 값을 보였다. 실험 결과로 부터 중간체 생성 과정이 반응속도 결정 단계임을 알았으며 용매효과는 메탄올의 산소 원자와 아닐린의 수소원자 사이의 수소결합에 의한 천이상태 안정화로 설명하였다.

• 약학회지
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• 제55권2호
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• pp.127-130
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• 2011

We synthesized new ${\alpha}$-amidoketenes using dehydrochlorination from anilines, triethylamine and malonyl dichloride under $0^{\circ}C$. The utility of ketenes in both laboratory and industrial practice was quickly recognized, and these species have been extensively utilized, including as pharmaceutical intermediates and anti-cancer agents. All synthetic process from anilines to ${\alpha}$-amidoketenes could be carried out by one-pot reaction. Synthetic ketenes 2a~f were identified using NMR and IR spectrum. Formation of ketenes was undertaken with dropping of malonyl dichloride at $0^{\circ}C$ in methylene chloride for 0.5~4 h. Using malonyl dichloride was better than using diethyl malonate as a synthetic reagents for the ketenes.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3218-3222
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• 2013

The aminolyses, anilinolysis and pyridinolysis, of bis(2-oxo-3-oxazolidinyl) phosphinic chloride (1) have been kinetically investigated in acetonitrile at 55.0 and $35.0^{\circ}C$, respectively. For the reactions of 1 with substituted anilines and deuterated anilines, a concerted SN2 mechanism is proposed based on the selectivity parameters and activation parameters. The deuterium kinetic isotope effects ($k_H/k_D$) invariably increase from secondary inverse to primary normal as the aniline becomes more basic, rationalized by the transition state variation from a backside to a frontside attack. For the pyridinolysis of 1, the authors propose a stepwise mechanism with a rate-limiting step change from bond breaking for more basic pyridines to bond formation for less basic pyridines based on the selectivity parameters and activation parameters. Biphasic concave upward free energy relationship with X is ascribed to a change in the attacking direction of the nucleophile from a frontside attack with more basic pyridines to a backside attack with less basic pyridines.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1096-1100
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• 2013

The kinetic studies on the reactions of O-methyl (1), O-propyl (3) and O-isopropyl (4) phenyl phosphonochloridothioates with substituted anilines and deuterated anilines have been carried out in acetonitrile at $55.0^{\circ}C$. A concerted $S_N2$ mechanism is proposed for the anilinolyses of 1, 3 and 4. The anilinolysis rates of the phosphonochloridothioates are predominantly dependent upon the steric effects over the inductive effects of the two ligands. The deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) are primary normal with 1 and 3, while secondary inverse with 4. Primary normal and secondary inverse DKIEs are rationalized by frontside and backside nucleophilic attack transition state, respectively. The DKIEs of the phosphonochloridothioates do not have any consistent correlations with the two ligands.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2801-2805
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• 2010

A nucleophilic substitution reaction of 4-chloro-7-nitrobenzofurazan (NBF-Cl) with anilines in MeOH-MeCN mixtures was conducted at 25, 35, and $45^{\circ}C$. Based on the higher $\beta_{nuc}$ values (1.0 - 1.6) of the reaction and a good correlation of the rate constants with the reduction potentials of the aniline nucleophiles, the present reaction was initiated by a single electron transfer (SET). After this step, the reaction proceeds through a transition state similar to the normal $S_NAr$-Ad.E pathway.

• 약학회지
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• 제52권6호
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• pp.514-519
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• 2008

We developed a convenient synthetic route to 3-alkylated 2-phenyl-4-quinolone derivatives (4a-h and 5a-c), which were expected to retain antitumor activity. A series of 2,3-dihydro-2-hydroxy-2-phenyl-4-quinolones (3a-h) was synthesized through dehydration, dealcoholation and hydration using acid-catalyzed one-pot reaction from anilines and ethyl benzoylacetates. 3-Methyl (or 3,3-dimethyl)-2-phenyl-4-quinolone derivatives 4 and 5 were synthesized from 3a-h through the methylation using methyl iodide. Formation of quinolone nucleus was undertaken with p-toluenesulfonic acid (p-TSA) at $90{\sim}110^{\circ}C$ in toluene for 3${\sim}$7.5 hr over the Dean-Stark apparatus. The key intermediates in these preparations are ${\beta}$-ketoesters 2a-h, which can be readily obtained from the corresponding anilines 1a-e by reaction with ethyl bezoylacetates.