• 대한화학회지
• /
• 제43권1호
• /
• pp.74-84
• /
• 1999

벤조트리아졸을 보조체로 사용하는 유기합성법은 거의 대부분 이온성 반응 메카니즘으로 설명되며 라디칼 반응을 이용한 벤조트리아졸의 응용은 거의 없었다. 벤조트리아졸의 N-1의 ${\alpha}$위치 탄소 원자에 라디칼 중심을 만든 후 벤조트리아졸의 다섯고리를 형성하는 질소 원자중에서 질소 분자가 빠져나감으로서 생성되는 페닐 라디칼의 반응을 연구하기위해 1[(aryl)(phenylseleno)methyl]benzotriazole, AIBN, 그리고 $Bu_3$SnH을 벤젠에 용해시키고 환류시켜 주었다. 이 반응 혼합물로 부터 2-aminodiphenyl selenide (16∼29%), 2-aminobiphenyl (9∼15%), diphenyl diselenide (30∼93%), 1-(arylmethyl)benzotriazole (9∼39%), 그리고 tributyltinphenyl selenide (10∼36%)을 얻었으며, AIBN없이 과량의 $Bu_3$SnH 존재하에 같은 조건하에서 반응시키는 경우,diphenyl diselenide (53∼100%), benzotriazole (27∼35%) 그리고 1-(arylmethyl)-benzotriazole (16∼33%)와 함께 arylmethylidenaniline이 과량의 $Bu_3S_nH$에 의해 환원된 N-(arylmethyl)anilines (44∼66%)이 생성되었다. 같은 조건 하에서 6-aryl-6-(benzotriazol-1-yl)-1-hexenyl phenyl selenides, AIBN, 그리고 $Bu_3$SnH의 반응으로부터 6-aryl-6-phenylamino-1-hexene(9∼31%)과 1-aryl-1-oxo-5-pentene (15∼44%)을 얻었다. 이들 생성물의 생성 메카니즘을 제시하였으며 벤조트리아졸이 합성 보조체로 이용된 경우 $Bu_3$SnH에 의해 벤조트리아졸의 세개의 질소 원자를 포함하는 다섯원자고리로 부터 라디칼 반응에 의해 질소 분자가 빠져나가는 것을 보여준 새로운 예이다.

• Bulletin of the Korean Chemical Society
• /
• 제20권11호
• /
• pp.1345-1347
• /
• 1999

• 대한화학회지
• /
• 제39권11호
• /
• pp.842-847
• /
• 1995

유리질 탄소전극을 사용하여 조사한 몇가지 N'-aryl-N-alkyl-N-nitrosourea 유도체들의 전기화학적 환원반응은 확산지배적이고 비가역적인 반응이었다. 이들 유도체들의 환원 반응시의 교환속도 상수 $k_0$값은 $1.48{\times}10^{-6}{\sim}5.32{\times}10^{-7}\;cm/sec.$의 값을 나타내었었다. Aryl기 및 alkyl기의 치환기에 따른 교환속도상수는 $k_0$ N'-aryl-N-alkyl-N-nitrosourea 에서 aryl기가 phenyl일 경우, 다른 치환기보다 $k_0$값이 1.3-2.8배였다. N'-aryl-N-alkyl-N-nitrosourea 와 N'-aryl-N-(2-chloroethyl)-N-nitrosourea의 두 화합물에서 aryl기의 치환기가 같을 경우는 비슷한 값을 나타내었다. N'-aryl-N-methyl-N-nitrosourea 유도체는 pH값이 높아짐에 따라 $E_p$값이 음전위쪽으로 이동하며 각 환원 반응에 참여한 $H^+$의 수는 4-5개였다. 이경우 aryl기의 치환기 효과는 환원전위에 크게 영향을 미치지 않는 것으로 나타났다.

• Bulletin of the Korean Chemical Society
• /
• 제11권3호
• /
• pp.241-244
• /
• 1990

The photochemistry of 1-Methyl-2-cyclohexenyl aryl ketones (phenyl ketone 7a, p-toluyl ketone 7b, biphenyl ketone 7c and -naphthyl ketone 7d) is reported. The aryl ketone 7a, 7b and 7c undergo photo-racemization with efficiencies of 0.75, 0.79 and 0.76 respectively on direct irradiation. Direct irradiation of the ketone 7d, however, undergoes 1,3-shift with an efficiency of 0.02. Triplet states are responsible for the racemizations and singlet state is responsible for 1,3-shift as in general. The ketone 7a, 7b and 7c are good example of a few ${\beta},{\gamma}$-unsaturated ketones which undergo efficient intersystem crossing on direct irradiation.

• Archives of Pharmacal Research
• /
• 제22권6호
• /
• pp.592-607
• /
• 1999

2-(1-Aryl-1-hydroxymethyl)-and 2-aroyl-DHAQ derivatives (DHAQ, 1,4-dihydroxy-,10-anthraquinone), and 2-(1-aryl-1-hydroxymethyl)-ATO derivatives (ATO, anthraceneactivity (T/C 125~128%), though their cytotoxicity was not further improved compared to that of 2-(1-aryl-1-dydroxymethyl)-1,4-dihydroxy-9,10-anthraquinones. They manifested no correlation between the cytotoxicity and the antitumor activity. In case of 2-[1-hydroxy-1-(4-propylphenyl)-methyl]-ATO, the most bioactive one in viv-1,4,9,10-tetraone) were synthesized and their antitumor activities were determined. 2-(1-Aryl-1-hydroxymethyl)-DHAQ derivatives showed a stronger cytotoxicity compared to the series of 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinone derivatives. It was suggested that the presence of aryl group at the side chain accelerated the bioreductive activation leading to cell death. 2-Aroyl-DHAQ derivatives, despite their higher electrophilicity, revealed smaller cytotoxicity and antitumor activity (expressed by T/C value) than 2-(1-aryl-1-hydroxymethyl)-DHAQ derivatives. Thus, no consistent relationship between the electronic effect on aromatic side chain and the cytotoxicity was observed. ATO series exhibited a higher antitumor o among the same series, it showed an $ED_{50}$ value of 10.2 mg/mL and a T/C value of 218%. It is assumed that the anthrancene1,4,9,10-tetraones after uptake into cellular tissues might be transformed to a cytotoxic metabolite(s).

• Bulletin of the Korean Chemical Society
• /
• 제32권6호
• /
• pp.1873-1878
• /
• 2011

Under solvent-free conditions and in one-pot, a series of 2-amino-4-aryl-3-cyano-6-(3,4-dimethoxyphenyl)-pyridines and 4-aryl-3-cyano-6-(3,4-dimethoxyphenyl)-2(1H)-pyridinones were prepared using 3,4-dimethoxyacetophenone, an aldehyde, malononitrile (or ethyl cyanoacetate), and ammonium acetate in the presence of 3-methyl-1-(4-sulfonylbutyl)imidazolium hydrogen sulfate $[HO_3S(CH_2)_4MIM][HSO_4]$ (a Br${\o}$nsted acidic ionic liquid) as the catalyst in very short reaction time. The preference for the formation of more stable tautomers was consistence with the theoretical calculation using the Gaussian 03 program at the B3LYP hybrid density functional level.

• Archives of Pharmacal Research
• /
• 제26권10호
• /
• pp.773-777
• /
• 2003

In this study, some new nitroimidazole derivatives were obtained from 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethylamine dihydrochloride (4) and 1-(2-bromoethyl)-2-methyl-5-nitroimidazole (5), which were prepared using metronidazole. Compound 4 was reacted with arylisothiocyanates (6) to obtain 1-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-3-arylthioureas (7) and the latter with $\alpha$-bromoacetophenones (8) to give -3-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-2-arylimino-4-aryl-4-thiazolines (9). Also 1-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-2-phenyl-4-arylideneimidazolin-5-ones (11) were prepared by reaction of 4 with 2-phenyl-4-arylidene-5-oxazolones (10). The reaction of the other starting material 5 with 5-arylidenethiazolidin-2,4-dione (12) gave 3-[2-(2-methyl-5-nitroimidazol-1-yl)ethyl]-5-arylidenethiazolidin-2,4-dione (13) derivatives. Structural elucidation of the compounds was performed by IR, $^1H-NMR$ and MASS spectroscopic data and elemental analysis results. Antimicrobial activities of the compounds were examined and moderate activity was obtained.

• Bulletin of the Korean Chemical Society
• /
• 제32권8호
• /
• pp.2628-2632
• /
• 2011

The nucleophilic substitution reactions of Y-O-aryl phenyl phosphonochloridothioates with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are kinetically investigated in acetonitrile at $55.0^{\circ}C$. The deuterium kinetic isotope effects (DKIEs) invariably increase from an extremely large secondary inverse ($k_H/k_D$ = 0.439; min) to a primary normal ($k_H/k_D$ = 1.34; max) as both substituents of nucleophile (X) and substrate (Y) change from electron-donating to electron-withdrawing. These results are opposite to the DKIEs on Y-O-aryl methyl phosphonochloridothioates, and can be rationalized by the gradual transition state (TS) variation from backside to frontside attack. The trigonal bipyramidal pentacoordinate TS is proposed for a backside attack, while the hydrogen-bonded, four-center-type TS is proposed for a frontside attack. The negative values of the cross-interaction constants (${\rho}_{XY(H)}$ = -0.38 for $XC_6H_4NH_2$ and ${\rho}_{XY(D)}$ = -0.29 for $XC_6H_4ND_2$) indicate that the reactions proceed by a concerted $S_N2$ mechanism.

• Bulletin of the Korean Chemical Society
• /
• 제14권4호
• /
• pp.497-499
• /
• 1993

Irradiation of 4-biphenylyl-4-methyl-2-cyclohexenone (5) in benzene or methanol produced trans-6-biphenylyl-5-methylbicyclo[3,1,0]hexan-2-o ne (5a) and 3-biphenylyl-4-methylcyclohex-2-enone (5b). Electronic configurations of the excited states for 5a and 5b were assigned as n, ${\pi}^*$ and ${\pi}$, ${\pi}^*$ triplet states respectively. Irradiation of 4-methyl-4(${\beta}$-naphthyl)-2-cyclohexenone in benzene or methanol gave 4-methyl-3-(${\beta}$ -naphthyl)-2-cyclohexenone (6a), which is thought to arise from ${\pi}$, ${\pi}^*$ triplet state.

• Archives of Pharmacal Research
• /
• 제13권3호
• /
• pp.240-245
• /
• 1990

Asymmetric 2, 6-dimethyl-4-aryl-1, 4-dihydropyridine-3, 5-dicarboxylate with [N-(3, 4-methylenedioxybenzyl)-N-methyl] aminoethyl group as the ester moiety and related 1, 4-dihydropyridine derivatives were prepared and tested for the effects on vascular smooth muscles. 2-6-dimethyl-4-(3'-nitrophenyl)1-4-dihydropyridine-3, 5-dicarboxylic acid 3-[N-(3', 4-methylenedioxybenzyl-N-methyl] aminoethyl ester 5-methyl ester (11) and 2, 6-dimethyl-4-(3'-nitrophenyl)-1, 4-dihydropyridine-3, 5-icarboxylic acid 3-[N-2', 3'-methylenedioxybenzyl)-N-methyl] aminoethyl ester 5-ethyl ester (150 showed potent vasodilating activities $IC_{50}$($10_{-8}M$) was 2, 6 and 2.7 for 11 and 15, compared with 3.5 for nicardipine.