• Applied Biological Chemistry
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• v.39 no.3
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• pp.227-234
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• 1996

4-Methyl-2,6,7-trioxa-1-phosphabicyclo [2,2,2] octane 1-sulfide (BPS), 4-Methyl-2,6,7-trioxa-1-phosphabicyclo[2,2,2] octane 1-oxide (BPO) and related monocyclic methylphosphates were prepared and the oxidation of BPS with MCPBA in chlorofrom or methanol was carried out to investigate the formation of reactive intermediates and reaction mechanism. BPO was the only product in chloroform while in methanol isomeric monocyclic methylphosphates were formed through opening of bicylic structure with subsequent phosphorylation of methanol by reactive intermediate formed in reaction. Formation of little amount of BPO was also observed. The structure of phosphorylating intermediate was probed with various spectroscopic methods and monocyclic methyl sulfenyl ester was suggested as a possible structure.

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.213-222
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• 2019

Birnessite (birnessite, $7{\AA}$ manganate, ${\delta}-MnO_2$) is a major mineral comprising manganese nodule. Various synthetic methods have been studied and evaluated because it can be used as an ion exchange agent and a battery recharging material. However, it is difficult to obtain a single birnessite phase because it does not have a stoichiometric chemical composition. Feitknechtite (${\beta}-MnOOH$) is formed as an intermediate product during birnessite synthesis and in this study, the transition of this phase to birnessite was compared by using XRD and SEM. Two different methods, Feng et al. (2004) and Luo et al. (1998), based on redox reaction were used. It was possible to obtain the impurity-free birnessite for the sample aged 60 days at $27^{\circ}C$ by Feng et al. (2004) method and 3 days at $60^{\circ}C$ by Luo et al. (1998) method. The phase transition rate of the feitknechtite phase was slower in the case of $Mg^{2+}$ doped birnessite which was synthesized by Luo et al. (1998) method, and almost single phase almost single phase birnessite was identified at high temperature. Crystal surface and morphology also confirmed the difference between the samples synthesized by two methods.

• Journal of Photoscience
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• v.3 no.1
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• pp.39-42
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• 1996

The photochemical reaction of phenyl(tribromomethyl)mercury with nido-decaborane gives a new boron cluster expanded compound. The two borons at the 6- and 9- positions in decaborane behave as electrophilic centers for the reaction with dibromocarbene. The first step in this reaction is the addition of two molar equivalents of dibromocarbene which is produced from phenyl(tribromomethyl)mercury to nido-decaborane. In the second step the unstable intermediate generates the product, 1,2-$Br_2C_2B_{10}H_{10}$ through loss of H$_2$.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.140-143
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• 1963

${\alpha}$-Ethyl-4,6-diiodo-2,3-dehydro-2,3,4,6-tetradeoxy-D-glucoside was synthesized from glucose through a modified Fischer et al. method. The yield of reduction process of an intermediate triacetylglucal, was markedly increased by utilizing lyophilization technique for removing the water in the reaction product.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.482-486
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• 2010

In this study, 2-(Nitroimino)imidazoline was prepared by the reaction of nitroguanidine with ethylenediamine in the presence of water at $65^{\circ}C$. The product was identified by using various analytical tools such as melting point, elemental analyzer, IR spectrophotometer, mass spectrometer and TLC. This compound can be used as intermediate for prepareing pesticide-imidacloprid packing and cosmetics preservative.

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.543-546
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• 1989

The photocycloaddition reaction of khellin with several olefins has been investigated. The photocycloadducts are formed regioselectively on furanyl 4',5'-double bond of khellin probably due to the localization of excitation energy on the furanyl 4',5'-double bond in the reactive excited state. The photocycloaddition reaction proceeds through the excited triplet state and the same product was formed when khellin is irradiated with dimethylfumarate or dimethylmaleate indicating the formation of common intermediate. The quantum yields of photocycloadduct formation, fluorescence, and intersystem crossing are very sensitive to proton-donating ability of solvents.

• Archives of Pharmacal Research
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• v.16 no.2
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• pp.94-98
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• 1993

Various hydrazines such as aryl-, carbonyl-, and sulfonyl-hydrazine were reacted with dinitrogen tetroxide to give the corresponding azides in excellent yields under mild ocnditions at low temperature $(-20-40^\circ{C)}$ in acetonitrile. The reaction appears to be initiated by formation of the .betha.-nitroso hydrazine intermediate which converts into the azide product.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.310-315
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• 1995

The heterobimetallic anion, (OC)5CrMn(CO)5-M+ (M+=Na+, PPN+), which has a donor-acceptor metal-metal bond1, was reacted with allyl bromide to yield BrCr(CO)5- and Mn(CO)5(CH2CHCH2). The reaction mechanism has been proposed in terms of the consecutive reaction pathway in which Cr(CO)5(THF) is an important intermediate leading to the corresponding product. Counterion effect on this reaction was also evaluated and the results were compared with those of the corresponding reaction of the mononuclear carbonyl anion, Mn(CO)5-.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.349-355
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• 1995

Bromo-and chlorotrimethylsilane react with selenium dioxide in halocarbon solvents and generate selenium oxybromide and oxychloride, respectively. These in-situ generated oxyhalides turned out to be very efficient for selective bromination and chlorination of aldehydes and ketones. Under carefully controlled reaction conditions, second and third introduction of halogens into carbonyl compounds can be greatly suppressed, and high yields of monohalo compounds were obtained. The product ratios of this halogenation reactions can be best explained if the reactions are assumed to involve intermediate β-ketoselenenyl chlorides.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1826-1829
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• 2003

Fine chemical production must assure high-standard product quality as well as characterized as multi-product production in small volumes. Installing high-precision batch distillation is one of the common elements in the successful manufacturing of fine chemicals, and the importance of the process operation strategy with quality assurance cannot be overemphasized. In this study, we investigate the optimal operation strategy and production planning of a sequential multi-purpose plants consisting of batch processes and batch distillation with unlimited intermediate storage. We formulated this problem as an MILP model. A mixed-integer linear programming model is developed based on the time slot, which is used to determine the production sequence and the production path of each batch. Illustrative examples show the effectiveness of the approach.