• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.871-877
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• 1994

Most of the aromatic nitro compounds were reduced to amines in high yield by transfer of hydrogen from 4-vinyl cyclohexene to the substrate via palladium catalyst. The usefulness of the method is not affected by the presence of a variety of other functional groups such as -OH, $-OCH_3$, $-CH_3$, $-CO_2H$, and -Cl, except for halogen which is removed during hydrogenation. The reduction of ortho-substituted nitrobenzene such as o-nitrotoluene, o-nitrophenol, o-nitroanisole was slower than the para isomer. Typically, the nitro compound is refluxed in ethanol with a large exess of 4-vinylcyclohexene in the presence of Pd-C catalyst. Under the above conditions, p-nitrobenzaldehyde, p-nitrobenzyl alcohol, and p-nitrobenzyl acetate were reduced to p-toluidine.

• Nuclear Engineering and Technology
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• v.5 no.3
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• pp.202-213
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• 1973

In a continuation of the 1st series of these studies, a separation of the components in organic phases obtained from Szilard Chalmer reactions of aromatic chloro derivatives was attempted to clarify the conditions of isolating the main component. Though it was unable to isolate all constituents of organic phases, the main component was well isolated by means of a simple distillation or a thin layer chromatography. It was identified that the main component was a recombined product of the recoiled $^{38}$ Cl atom with the original sample. In cases of solid samples the main component amounted about 80-60% of the radio activity of the organic phase, whereas the main component from liquid samples gave less than 70% of the radio activity of the organic phase. A prolonged irradiation could increase the yield of a main component, but it was, in case of a radiation senintive compound, decreased as the irradiation is extended. The number of aide produets separated from an organic phase of a liquid sample was greater than that of a solid sample, and hence the main component of a solid sample was isolated easier. The overall fields of the labelled main products of 22 kinds of compounds were listed and a procedure of the separation of the main component by a thin layer chromatograply was proposed and evaluated. The feasibility of the present procedure for labelling purpose was also reviewed with respects to the chemical structure of a compound.

• Elastomers and Composites
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• v.38 no.1
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• pp.72-80
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• 2003

Phosphoric ester compound was employed as thermal resistant and flame retardant for chlorinated polyethylene(CPE) rubber material which is used to prepare automotive oil cooler hose. Cure characteristics, physical properties, thermal resistance, and flame retardation of CPE rubber compounds were investigated. CPE rubber which has excellent properties such as cold resistance and chemical corrosion resistance, and is inexpensive in price than existing ethyleneacrylate rubber(EAR) was used to prepare a rubber compound useful for hose. A non-halogen flame retarding agent N,N'-bis- (diphenylphosphoro) diaminohexane(BDPDH), which is condensed phosphoric ester, was synthesized and it was mixed to CPE rubber material with the range of $0{\sim}30 phr$. From the test results, rheological properties, heat resistance, and flame retardance of CPE rubber compounds were found out to be much increased. The optimum content of BDPDH to rubber which gives maximum effect on thermal resistance and flame retardation, within the range of tolerable specification for rubber materials, was determined to be 20 phr.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.176-182
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• 2023

Among 14 subtypes of serotonin receptors (5-HTRs), 5-HT_2AR plays important roles in drug addiction and various psychiatric disorders. Agonists for 5-HT_2AR have been classified into three structural groups: phenethylamines, tryptamines, and ergolines. In this study, the structure-activity relationship (SAR) of phenethylamine and tryptamine derivatives for binding 5-HT_2AR was determined. In addition, functional and regulatory evaluation of selected compounds was conducted for extracellular signal-regulated kinases (ERKs) and receptor endocytosis. SAR studies showed that phenethylamines possessed higher affinity to 5-HT_2AR than tryptamines. In phenethylamines, two phenyl groups were attached to the carbon and nitrogen (R³ ) atoms of ethylamine, the backbone of phenethylamines. Alkyl or halogen groups on the phenyl ring attached to the β carbon exerted positive effects on the binding affinity when they were at para positions. Oxygen-containing groups attached to R³ exerted mixed influences depending on the position of their attachment. In tryptamine derivatives, tryptamine group was attached to the β carbon of ethylamine, and ally groups were attached to the nitrogen atom. Oxygen-containing substituents on large ring and alkyl substituents on the small ring of tryptamine groups exerted positive and negative influence on the affinity for 5-HT_2AR, respectively. Ally groups attached to the nitrogen atom of ethylamine exerted negative influences. Functional and regulatory activities of the tested compounds correlated with their affinity for 5-HT_2AR, suggesting their agonistic nature. In conclusion, this study provides information for designing novel ligands for 5-HT_2AR, which can be used to control psychiatric disorders and drug abuse.

• Journal of the Korean Chemical Society
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• v.9 no.2
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• pp.88-95
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• 1965

The exo adduct between furfuryl derivatives (furan, furfuryl acetate and furfuryl alcohol) and maleic anhydride were prepared in the presence of ethyl ether. The bromination of the exo adduct of each derivatives gave a monobromolactone and dibromoacid when the reaction was done in the presence of water. The formation of the bromolactone was proved to be dependent to the carboxylic participation to the incipient rearranged carbonium ion of a classical type, and the participation was sterically hindered by the steric structure of the substituents. The bromination of the furan-maleic anhydride adduct in the presence of organic solvent $(CCl_4,\;CH_2Cl_2)$ gave the dibromide, whereas the photochlorination of the same adduct in the presence of carbon tetrachloride gave the tetrachloride. The procedure of the preparation and the reaction path of the halogenation were described.

• Journal of the Korean Chemical Society
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• v.24 no.2
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• pp.108-114
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• 1980

By using electrostatic model and simple bond additivity scheme a reasonable and simple method was developed for the estimation of standard enthalpy of formation $({\Delta}H_f\;^{\circ})$ of very polar compounds. The bond contributions to the enthalpy of formation for halomethanes were; ${\Delta}H_f\;^{\circ}(C-F)=-36.44\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-Cl)=-2.57\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-Br)=5.32\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-I)=19.18\;kcal/mole,\;and\;{\Delta}H_f\;^{\circ}(C-H)=-3.61\;kcal/mole$, respectively. Using these values and calculated electrostatic energies, the estimated ${\Delta}H_f\;^{\circ}$ values were estimated and found to be in good agreement with observed values.

• Environmental Engineering Research
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• v.23 no.4
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• pp.345-353
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• 2018

This paper summarizes results of research on the electrochemical (EC) degradation of disinfection by-products (DBPs) and iodine-containing contrast media (ICMs), with the focus on EC reductive dehalogenation. The efficiency of EC dehalogenation of DBPs increases with the number of halogen atoms in an individual DBP species. EC reductive cleavage of bromine from parent DBPs is faster than that of chlorine. EC data and quantum chemical modeling indicate that the EC reduction of iodine-containing DBPs (I-DBPs) is characterized by the formation of active iodine that reacts with the organic substrate. The occurrence of ICMs has attracted attention due to their association with the generation of I-DBPs. Indirect EC oxidation of ICMs using anodes that produce reactive oxygen species can result in a complete degradation of these compounds yet I-DBPs are formed in the process. Reductive EC deiodination of ICMs is rapid and its overall rate is diffusion-controlled yet I-DBPs are also produced in this reaction. Further progress in practically feasible EC methods to remove DBPs, ICMs and other trace-level organic contaminants requires the development of novel electrocatalytic materials, elimination of mass transfer limitations via innovative design of 3D electrodes and EC reactors, and further progress in the understanding of intrinsic mechanisms of EC reactions of DBPs and TrOC at EC interfaces.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.20-28
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• 1999

Chloronicotinyl derivatives were synthesized by substitution of amino in 3-pyridylmethylamine with phosphite groups and their insecticidal and fungicidal activities were determined. At 500 ppm, compound 4 with methyl and butyl group in phosphonate and compound 5, 6, 7, and 8 with two butyl, 2,2,2-trifluorotehtyl, 2-ethylhexyl, phenyl, respectively, in phosphonate showed 90% insecticidal activities against brown plant-hopper (Nilaparvate lugens). These compounds showed, however, poor insecticidal activities against diamond-back moth (Plutella xylostella) and two-spotted spider mite (Tetranychus urticae) (<65%), suggesting that insecticidal activity of chloronicotinyl derivatives containing phosphorus moieties are species-dependent. Newly synthesized chloronicotinyl derivatives with halogen and/or heterocycle (compound $10{\sim}21$) did not show insecticidal activities. We also determined fungicidal activity of the synthesized chloronicotinyl derivatives against rice sheath blight (Pyricularia grisea), cucumber gray mold (Bortytis cinerea), tomato late blight (Phytophthora infestans), wheat leaf rust (Puccinia recondita), and barley powdery mildew (Erysiphe graminis). Compound 10 with butyl and 4-nitrophenyl in phosphonate at 10 ppm showed 85% fungicidal activity against rice blast, suggesting that chloronicotinyl derivatives containing phosphorus moieties could be developed as a fungicidal agent of a novel chemical structure.

• Journal of environmental and Sanitary engineering
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• v.6 no.1
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• pp.7-25
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• 1991

Until now, pure drinking water grnerally menas the water without taste, odor, general bacteria, coliform, and other exotic substance. Such a definition has been changing recently due to the finding of numerous other inorganic and organic substances unknown to us. 10 years ago, major causes of death were infectious agents and parasites contained in water, but recently, it has become apparent that some substances contained in drinking water cause cancer and heart diseases. We must drink about 2L of water everyday in order to maintain healthy condition. Waters used for drinking include tap water, well water, spring water, filtered water, etc., but the quality of drinking water has more polluted due to the industrial development and population increase. For example, industrial waste waters from industrial plants pollute the water supply sources ; toxic substances contained in the waste waters pollute the ground water sources by penetrating the geological strata, and municipal, livestock, public building waste waters also pollute the water supply sources. Sometimes, the polluted surface waters were announced to be polluted by various kinds of orgainc substance, and it is reported that the pollution of ground water by orga nic substances has few in number but high in its concectration comparing with those of surface water. As the water quality pollution level increases, so the amount of disinfectant also increase. For example, chlorine solution, one of widely used disinfectants, creates trihalomethane(THM), a carcinogen, and halogen compounds. According to Oliver, through chlorine disinfection process, humine substance and chlorine create bolatile organic halide and nonvolatile organic halide by chemical reaction. There are tens or hundreds filtering devices, but filtering principles and maintenance metjhods are different, so their efficiency tests are needed. According to Smith, the effeciency tests aginst over 30 Ameican filtering devices show that 10 devices can remove 85% of volatile organics and further studies on filtered waters are underway. In consideration of important impacts of polluted drinking water on national health, authors studied the state of water quality pollution against tap water used as drinking water, filtration device passed water, ground water, and conserved drinking water ; tested the efficiency of filtration devices for tap water ; tried to sep up the detection method by using ion chromatography based on negative ion and positive ion by using single column, and attemped the simple filtration method for general households.

• Journal of the Korean Chemical Society
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• v.9 no.1
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• pp.1-7
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• 1965

Reaction of monochloroacetic acid with zinc in presence of toluene, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, and dioxane solvents showed the solvent effect in order of dimethylformamide, dioxane, dimethyl sulfoxide, toluene, acetonitrile, and tetrahydrofuran. The increasing reactivity of the reagents was observed in order of the polarity and hydrophilicity of the solvent. The same reaction of ethyl monochloroacetate in the same series of solvents showed also the solvent effect, but the difference was not large as compared to that of the acid. The reaction of the acid, ester, zinc, and carbonyl precursors such as benzaldehyde and 4-heptanone gave the Reformatsky reaction product in the case of the aldehyde, but the reactivity with 4-heptanone was slight. The yield of the product was varied by the method of addition of reagents. The best yield observed in case of the acid reaction was 38.5% of the hydroxy acid and 0.8g of the salt in presence of acetonitrile and in case of the ester reaction 19.3% of ethyl cinnamate and 21.6% of polymer. The variation of the reactivity of reagents due to the reaction temperature was observed in case of carbonyl reaction. The result was discussed in terms of the solvent effect and the procedures were described.