• Korean Chemical Engineering Research
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• 제43권2호
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• pp.202-205
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• 2005

GoAgg 생체모방계 산화반응시스템을 이용하여 상온, 상압에서 시크로헥산을 산화 반응하여 시크로헥산올과 시클로헥산온 제조를 위한 연구를 수행하였다. 반응속도론적 연구를 수행하였으며 리간드로 카르복실기를 포함하는 picolinic acid를 사용한 경우 철 촉매만 사용한 경우에 비해 15배 이상의 활성이 증가하였다. 특히 피리딘환이나 이미다졸환에 ortho 위치에 카르복실기를 포함한 경우 meta, para 위치보다 반응성이 크게 증가하였다. 이 결과로부터 새로운 매커니즘을 제안하였다.

• 대한화학회지
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• 제18권4호
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• pp.272-277
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• 1974

분배계수와 용매의 용해도 파라미터 도표상의 추출포물선을 검토하여 질산산성에서 유로퓸을 TBP로 추출할 때 유로퓸착물과 TBP의 활동도 계수간의 관계를 알 수 있었고 이에 따라 TBP의 용해도 파라미터를 결정하는 가능성을 제시하였다. 용매로서는 cyclohexane, 벤젠, 톨루엔, chlorobenzene을 사용하였고 TBP의 농도를 용적백분율로 5에서 50까지 변화시켰다.

• 대한화학회지
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• 제50권2호
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• pp.129-136
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• 2006

마이오 이노시톨을 이용한 새로운 고분자 리간드를 합성하였다. 형태적으로 안정한 이노시톨 고분자를 얻기 위해 고리화 고분자반응을 시도하였으며, 고리화의 메커니즘 및 고리 구조가 입증되었다. 또한, 분광학적 비교 방법을 이용해 합성된 고분자들의 형태가 밝혀졌다. 마이오 이노시톨 카보네이트를 이용해 형태적으로 고정된 고분자 리간드를 성공적으로 합성하였다.

• 약학회지
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• 제22권4호
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• pp.238-241
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• 1978

A simple and convenient method of detecting N, N-dimethy laniline (D.M.A.) residues in ampicillin trihydrate (A.T.) was established. D.M.A. was extracted by chloroform from the chloroform presaturated N/10-ammonia water solution of A.T. and chromatographed on silica gel G thin layer. Blue spot appeared in 15minutes after spray of 2, 6-dichloroquinonechlorimide solution was compared with the blue spot of reference concomitantly processed. The developing solvent was prepared by mixing equal volume of cyclohexane and chloroform. To quantitate the amount of D.M.A. in A.T., T.L.C. was performed with the Eastmann Chromatogram sheet, then color density was measured by Cosmo Superclick densitometer. The developing solvent at this time was cyclohexane-chlorofonn (3+7) mixture. The peak areas obtained with the amount of D.M.A ranging from 0.05 to 2.0 .mu.g were linear to color density. Better sensitive results would be available with the densitometer equipped with monochromator.

• 한국환경보건학회지
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• 제6권1호
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• pp.23-26
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• 1979

한국에서 사용하고 있는 carbamate계 살충제의 사용율(%)은 1968년경에는 2.1%인데 비해서 현재는 급증되고 있는 실정에 있다. 따라서 이로 인한 자타살 사건, 환경오염, 살포시 급만성 중독 등의 사고가 빈번히 발생하고 있는 동시에 법화학적 분석에도 많은 문제점이 되두되고 있으므로 1차적으로 시판되고 있는 carbamate계 살충제를 thin layer chromatography에 의해서 성분의 분리 확인 시험을 실시한 결과 1) Silica Gel G-60 및 Silica Gel F-254에서 적합하였고 2) 전개용매는 chloroform: benzeneP: carbontetra chloride (60:30:25), cyclohexane: acetone (80:20), cyclohexane:acetone(70:30), ether:hexane(80:20)에서 9종의 살충제가 잘 분리되었으며 3) UV light (2537 ${\AA}$) 및 2.6-dibromoquinone-4-chlorimide는 전개는 Rf치를 육안으로 구분하는데 가장 양호하였고 4) Carbamate계 살충제 중 Bux-2와 Sevin은 Silica Gel G-60에서 UV light (2537 ${\AA}$)에서 특이한 청보라 및 청색형광을 관찰할 수 있었다. 5) 이상의 결과를 보아 법화학적 시료중에 함유된 카바메이트계 농약의 분석은 가능할 것이며 또한 이 방법의 적용이 현재의 실정으로서는 적합한 것으로 사료되는 바이다.

• Journal of Pharmaceutical Investigation
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• 제18권4호
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• pp.187-195
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• 1988

Poorly permeable $Eudragit^{\circledR}$ RS 100 polymer was used as a wall material for the microencapsulation of zipeprol dihydrochloride by a phase separation method from chloroform-cyclohexane system with 5% polyisobutylene in cyclohexane, and microcapsules obtained were evaluated in vitro by particle size analysis, scanning electron microscopy, drug release test and in vivo bioavailability test in rats. The mechanism of drug release from microcapsules appeared to fit Higuchi matrix model kinetics. The area under the first moment of plasma concentration-time curve of the microcapsules obtained was considerably increased (p<0.05) as compared with that from zipeprol dihydrochloride oral solution. Therefore, it may be suggested that $Eudragit^{\cirledR}$ RS 100 coated zipeprol dihydrochloride microcapsules can be used as a sustained release medication.

• Bulletin of the Korean Chemical Society
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• 제16권5호
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• pp.398-400
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• 1995

Selective oxidation of cyclohexane in acetone solution has been studied using iron catalysts with hydrogen peroxide in-situ produced by palladium catalyst. Iron tetraphenylporphyrin chloride shows the highest activity among the tested chlorides and porphyrin complexes of some metals of the first transiton series. Iron chloride and iron tetraphenylporphyrin chloride were supported on four kinds of 4-vinylpyridine copolymer with styrene or divinyl-benzene. Nitrogen 1s photoelectron spectra give the evidence that pyridyl nitrogens of the 4-vinyl pyridine copolymer act as ligands to bind iron species. The copolymer with styrene is the most efficient support for the binding because its solubility in catalyst preparation solvent (methylene chloride) gives the pyridyl group advantage to contact with the iron catalysts. However, better catalytic activity per iron atom could be obtained with a rigid crosslinked polymer due to active site isolation.

• Bulletin of the Korean Chemical Society
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• 제12권5호
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• pp.483-487
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• 1991

The tetraaza macrocyclic ligand 3,14-dimethyl-2,6,13,17-tetraazatricyclo $[14,4,0^{1.18} ,0^{7.12}]$docosa-2,12-diene(B), that contains two cyclohexane rings, has been prepared as its dihydroperchlorate salt by the nontemplate condensation of methyl vinyl ketone with 1,2-diaminocyclohexane and perchloric acid. Reduction of B with sodium borohydride produces 3,14-dimethyl-2,6,13,17-tetraazatricyclo$[14,4,0^{1.18},0^{7.12}]$docosane(C). Square planar Ni(Ⅱ) and Cu(Ⅱ) complexes of B and C have been prepared by the reaction of the metal ions and the ligands. Synthesis, characterization, and the properties of the ligands and their metal complexes are reported.

• Bulletin of the Korean Chemical Society
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• 제18권12호
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• pp.1269-1273
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• 1997

The system which employs iron, palladium, molecular oxygen and hydrogen as a model mono-oxygenase, has been investigated to develop a new method for selective cyclohexane oxidation uner mild conditions. This system provides much higher yield and selectivity for the formation of cyclohexanol and cyclohexanone compared to that of the existing industrial method. When the catalytic system, FeCl2-Pd/alumina, was employed, the oxidation system required acetone as a solvent to be efficient and acidifying the solvent by a little addition of acetic acid or HCl made the system more efficient. The Pd catalyst was recyclable without a significant deactivation but the recycling of ferrous chloride showed the decrease in the activity. On the other hand, the heterogeneous catalytic system, Pd/Fe2O3 could be recovered easily and reused after drying treatment.

• Bulletin of the Korean Chemical Society
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• 제17권7호
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• pp.625-630
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• 1996

The cobalt-substituted polyoxotungstate [(CoPW11O39)5-] has been used as a catalyst in olefin epoxidation and alkane hydroxylation reactions. The epoxidation of olefins by iodosylbenzene in CH3CN yielded epoxides predominantly with trace amounts of allylic oxidation products. cis-Stilbene was streoselectively oxidized to cis-stilbene oxide with small amounts of trans-stilbene oxide and benzaldehyde formation. The epoxidation of carbamazepine (CBZ) by potassium monopersulfate in aqueous solution gave the corresponding CBZ 10,11-oxide product. Other transition metal-substituted polyoxotungstates (M=Mn2+, Fe2+, Ni2+, and Cu2+) were inactive in the CBZ epoxidation reaction. The cobalt-substituted polyoxotungstate also catalyzed the oxidation of alkanes with m-chloroperbenzoic acid to give the corresponding alcohols and ketones. The presence of CH2Br2 in the hydroxylation of cyclohexane afforded the formation of bromocyclohexane, suggesting the participation of cyclohexyl radical. In the 18O-labeled water experiment, there was no incorporation of 18O into the cyclohexanol product when the hydroxylation of cyclohexane by MCPBA was carried out in the presence of H218O. Some mechanistic aspects are discussed as well.