• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.233-242
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• 2012

A new synthetic method for dimethyl 2,3-dihydrobenzo[b]oxepine-2,4-dicarboxylates and methyl 2-(2-carbomethoxybenzo[b]furan-3-yl)propanoates by an intramolecular conjugate displacement reaction or an $S_N2$ reaction of acetates of Morita-Baylis-Hillman adducts of methyl (2-formylphenoxy)acetates has been described.

• Korean Journal of Crystallography
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• v.10 no.2
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• pp.119-124
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• 1999

X-선 회절법을 이용하여 3,6-bis(6'-methyl-2'pyridyl)pyridazine을 리간드로 한 Zn(Ⅱ) 착물인 [3,6-bis(6'-methyl-2'pyridyl)pyridazine]ZnCl2 (C16H16N4·ZnCl2)의 결정구조를 규명하였다. 이 결정의 결정계는 Monoclinic이며 공간군은 P21/a이다. 단위포 상수는 a=15.053(7) Å, b=14.594(7) Å, c=7.628(3) Å이며, β=93.92(4)°, V=1671.9(13) Å3, T=293(2)K, Z=4, Dc=1.594 Mgm-3이다. 회절반점들의 세기는 Enraf-Nonius CAD-4 diffractometer로 얻었으며 Mo Kα선(λ=0.71073 Å)을 사용하였다. 분자구조는 직접법으로 풀었으며, Fo>4σ (Fo)인 1750개의 독립 회절 데이터에 대하여 최소승자법으로 정밀화하여 최종 신뢰도 값 R=8.31%을 얻었다.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.503-507
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• 2001

trans-Metanicotine, a subtype (${\alpha}_4{\beta}_2$)-selective ligand for neuronal nicotinic acetylcholine receptor, is under clinical phase for Alzheimer's disease. An efficient synthetic route for ($\pm$)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-am ices, derivatives of tracts-metanicotine, was explored. Allylation reaction of aryl aldimines with allylmagnesium bromide in THF gave ($\pm$)-methyl-(1-aryl-but-3-enyl)-amines. Protection of the amines with the Boc group and following Heck reaction of the N-Boc amines with 3-bromopyridine gave ($\pm$)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-carbamic acid tert-butyl esters. Deprotection of the N-Boc group in aqueous 1 N-HCI solution gave the titled amines in good yields. Thus, trans-metanicotine analogues modified at the ${\alpha}-position$ of the methylamino group with amyl groups were obtained in 5 steps.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1151-1156
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• 2014

The photocatalytic decomposition characteristics of single n-pentane, n-pentane mixed with methyl ethyl ketone (MEK), and n-pentane mixed with ethyl acetate (EA) by cylindrical UV reactor installed with $TiO_2$-coated perforated plane were studied. The effects of the residence time, the inlet gas concentration, and the oxygen concentration were investigated. The removal efficiency of n-pentane was increased with increasing the residence time and the oxygen concentration, but decreased with increasing the inlet concentration of n-pentane. The photocatalytic decomposition rates of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA fitted well on Langmuir-Hinshelwood kinetics equation. The maximum elimination capacities of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA were obtained to be $465g/m^3{\cdot}day$, $217g/m^3{\cdot}day$, and $320g/m^3{\cdot}day$, respectively. The presence of coexisting MEK and EA vapor had a negative effect on the photocatalytic decomposition of n-pentane and the negative effect of MEK was higher than that of EA.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.221-227
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• 1996

Micellization range and cmc for the dilute aqueous solution of N-acyl amino acid type anionic surfactants, that is, sodium N-acyl-N-methyl-${\beta}$-alaninate, sodium N-acyl sarcosinate and sodium N-acyl-N-methyl taurate were investigated by computer programming. The extreme of the curvature of ${\sigma}(C)$ as a new suggested method to determine the cmc and the micellization range was accomplished with computer programming. The values of cmc and micellization range can be obtained by the extreme of the curve by direct processing of only a few experimental data. The values of cmc particulary was in good agreement with those deduced intuitively from the shape of experimental curves of ${\sigma}(C)$.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.28-33
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• 1994

This study was conducted to investigate the efficacy of weed control by pyributicarb{O-[3-tert-butylphenyl] N-[6-methoxy-2-pyridyl]-N-methyl thiocarbamate}/bensulfuron-methyl{methyl 2-[[[[[[4, 6-dimethoxypyrimidin-2-yl] amino] carbonyl] amino] sulfonyl] methyl] benzoate} SC and oxadiazon{5-tert-butyl-3-[2,4-dichloro-5-isopropoxyphenyl]-1,3,4-oxadiazol-2(3)-one}/bensulfuron-methyl SC, and to develope weed control methods for paddy rice. There was little difference between suspension concentrate and granule of pyributicarb/bensulfuron-methyl and oxadiazon/bensulfuron-methyl combination in the effect of weed control. Pyributicarb/bensulfuron-methyl SC and oxadiazon/bensulfuron-methyl SC were diffused from the point of application to 6m. Pyributicarb/bensulfuron-methyl SC applied on water surface from irrigation inlet and in paddy water from dike controlled more than 90% of weeds. Pyributicarb/bensulfuron-methyl SC was precipitated about 1-2cm per 1 hour after dripping on water surface. The efficacy of weed control by pyributicarb/bensulfuron-methyl SC was higher in 0-1cm than in 6-7cm standing water depth.

• Ocean and Polar Research
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• v.36 no.3
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• pp.247-254
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• 2014

In our continuing study on the antioxidant activity of Polysiphonia stricta, its crude extract was fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions according to solvent polarity. The solvent fractions were evaluated for their potential to inhibit lipid peroxidation and reactive oxygen species (ROS) production in HT 1080 cells. The n-BuOH fraction most strongly inhibited both lipid peroxidation and ROS production in HT 1080 cells. The n-BuOH fraction was further separated by repeated silica gel column chromatography and RP-HPLC to give methyl aconitates (2 and 3). The chemical structure of isolated compounds was determinated by NMR spectral analysis.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.169-174
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• 2011

The synthesis of new pyrazolyl and cyclopropyl derivatives of purpurin-18 methyl ester and purpurin-18-N-butylimide 1a, 1b, 2a, 2b and 8 is described. The new compounds were characterized by NMR, UV-vis spectroscopy and mass spectrometry. UV-vis spectra of the new compounds showed long wavelength absorption of ranges 692 - 708 nm ($\lambda_{max}$). Photodynamic effects of the chlorin derivatives 1a, 1b, 2a and 2b were investigated by WST-1 assay in A549 cells, and showed good photodynamic activities with high photocytotoxicity and low cytotoxicity in the dark. In comparison between pyrazolyl and cyclopropyl derivatives, purpurin-18 methyl ester compounds 1a and 1b showed comparable photocytotoxicity result of the cell viabilities, otherwise, pyrazolyl derivative of purpurin-18-N-butylimide 2a showed better cell viabilities than those of cyclopropyl derivative 2b. And cyclopropyl derivative of purpurin-18-N-butylimide 2b showed higher dark cytotoxicity than that of others.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.851-856
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• 2002

The Reaction of S-methyl-S-cysteine(L-Smc) with racemic $s-cis-[Co(demba)Cl_2]-1$ (Hydmedba = $NN'-dimethylethylenediamine-NN'-di-\alpha-butyric$, acid) yields ${\Delta}$-s-cis-[Co(dmedba)(L-Smc)] 2 with N, O-chelation. Oxidation of sulfur of 2 with $H_2O_2$ in a 1 : 1 mole ratio gives ${\Delta}$-s-cis[Co(dmedba)(L-S(O)mc)] 3 having an uncoordinated sulfenate group. Oxidation of sulfur of L-Sm with $H_2O_2in$ a 1: 1 mole ratio produces S-methyl-L-cysteinesulfenate (L-S(O)me) 5. Direct reaction of 1 with 5 in basic medium gives an N.O-chelated ${\Delta}$s-cis[Co(dmedba)(L-S(O)mc)-N.O], which turmed out be same as obtained by oxidation of 2, while an N, S-chelated ${\Delta}$-s-cis-[Co(dmedba)(S-S(O)mc)-N,O] complex 4 is obtained in acidic medium from the reaction of 1 with 5. This is one of the rare $[$Co^{III}$(N_2O_2-type$ ligand)(amino acid)] type complex preparations, where the reaction conditions determine which mode of N, O and N, S caelation modes is favored.

• Journal of the Korean Chemical Society
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• v.56 no.4
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• pp.459-463
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• 2012

8-Formyl-4-Methyl-7-Hydroxy Coumarin Derivatives were synthesized via Penchem condensation followed by Duffs reaction. Treatment of this with N,N-di substituted cyano acetamides in the presence of piperdine afforded New 8-Formyl-4-Methyl-7-Hydroxy Coumarin Derivatives (7a-o). Their structures were characterized by IR, $^1H$ and $^{13}C$ NMR and Mass spectral and elemental analysis data.