• Title/Summary/Keyword: 브롬화메틸

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Debromination of 3-(1,2-Dibromo-2-methylpropyl)-1,2-isoxazolines to 3-(2-Methyl-1-propenyl)-1,2-isoxazolines by Sodium Thiolates (3-(1,2-디브로모-2-메틸프로필)-1,2-이속사졸린들의 나트륨 티올레이트들에 의한 탈브롬화 반응을 통한 3-(2-메틸-1-프로페닐)-1,2-티올레이트들에 의한 탈브롬화 반응을 통한 3-(2-메틸-1-프로페닐)-1,2-이속사졸린들로의 변환반응)

  • Kim, Hyeong Cheol;Jo, Su Yeon;Jeon, Dong Ju;Kim, Hyeong Rae
    • Journal of the Korean Chemical Society
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    • v.45 no.6
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    • pp.608-611
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    • 2001
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Effect of Fumigation on the Strength of Excavated Costumes (훈증처리가 출토복식유물의 강도 변화에 미치는 영향)

  • 채옥자;박성실;안춘순
    • The Research Journal of the Costume Culture
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    • v.12 no.4
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    • pp.591-598
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    • 2004
  • This study examines the effects and influences of fumigation using chemical composite of Methyl Bromide and Ethylene Oxide on the change of strength of excavated dresses. The fabric strength immediately after washing and fumigation increased slightly, but it decreased greatly as the time progressed. The strength of the test sample from Museum A showed a steady decrease with time, while that of Museum B decreased rapidly 5 months later. Compared with the non-fumigated sample, fumigated sample was greater in strength regardless of the time progression, and the strength of sample kept in the exhibit hall was greater than that kept in the storage room. The strength of the fumigated sample was almost same regardless of the three different time periods, before washing, after washing and immediately after fumigation, and it decreased steadily with time, whereas the non-fumigated sample became much weaker in its strength in 10 months after washing. Even 5 months later, the fumigated sample was about as strong as immediately after fumigation, but the strength dropped to a great extent 10 months later.

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A Synthesis of Solanone (솔라논의 합성)

  • Yong Tae Kim;Kwang-Kyu Yang;Kun Soo Kim;Sung Chul Shin
    • Journal of the Korean Society of Tobacco Science
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    • v.10 no.2
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    • pp.137-139
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    • 1988
  • A total synthesis of solanone was investigated. 4-Cyano -2-isopropylbutanal was treated with methallyl iodide in the presence of metallit tin, alominium and HBr to obtain 7-cyano-5-isopropyl-4-hydroxy-2-methyl-1-heptene, which was contacted with phosphorus oxychloride, followed by methylation of dienonitrile, yielded the solanone.

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Synthesis of Conjugated Dienals by Palladium-Catalyzed Vinyl Substitution Reaction (팔라듐 촉매화 비닐 치환 반응을 이용한 Conjugated Dienals의 합성)

  • Jong-Tae Lee;Jin Il Kim
    • Journal of the Korean Chemical Society
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    • v.28 no.5
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    • pp.335-341
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    • 1984
  • Acetals of ${\alpha},{\beta}$-unsaturated aldehydes reacted readily with aryl bromides in the presence of palladium catalyst and triethylamine to form aryl conjugated enals. Acrolein diethyl acetal and methacrolein diethyl acetal were reacted with phenyl bromides with substituents such as methyl and isopropyl groups at $100^{\circ}C$. The reaction products yields except the reaction of o-bromotoluene with methacrolein diethyl acetal. The products were identified by proton nuclear magnetic resonance and infrared spectroscopy. In the reverse combination of reactants to prepare aliphatic 2,4-dienals in good yield of above 50%, 3-bromopropenal dimethyl acetal and (E)-3-bromo-2-methylpropenal diethyl acetal were used as vinylic halide reactants and 1-alkenes and ethyl acrylate as olefin reactants.

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The Stability Appraisement on Cultural Property Material with the Replacing Fumigation Gas of Methyl Bromide (Methyl Bromide를 대체하는 훈증 가스의 문화재 재질 안정성 평가)

  • Kang, Dai-Ill
    • Journal of Conservation Science
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    • v.25 no.3
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    • pp.283-291
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    • 2009
  • Methyl Bromide that was used as fumigation gas turned out to be the substance of destroying the ozone layer. For that reason, at the Montreal Protocol in 1987 the use of methyl bromide was forbidden starting 2005 in the advanced country. Also according to the 2007 Bali Protocolly methyl bromide is expected to be forbidden and therefore the purpose of this study is to find out the effects of substitution fumigation gas (Ethylene Oxide+HFC 134a, Methyl Iodide, Cyanogen and Argon) on the metal(silver, copper and iron), wood(oregon pine), pigment(yellow, red, blue, white and black), textile(hemp, ramie, jute, silk1 and silk2 / indigo, safflower and cork) and paper. After the fumigation test, ethylene oxide+HFC 134a did not have changes in the weight and color of the material itself before and after the experiment. On exterior alteration, color change occurred partly on paper and metal. Also, in most materials color change extent was 0.5 to 1.5 on the average and showed scanty difference. The materials after the fumigation test with methyl iodide did not show weight changes after the test. However, color changes more than 1.0 was shown in most of the materials especially in dyed textile material. In blue pigment, the discoloration on the surface could be seen by naked eyes. Fumigation test with cyanogen gas did not show weight changes and discoloration is more than 1.5 before and after the test. The weight changes of test materials with the argon gas was decreased about 3 to 6%. It can be observed that discoloration on paper was generated. Color changes can be seen on jute dyed with safflower and cork for two weeks with argon gas and the extent was 6.3 and 6.0.

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Reversed-Phase Ion-Pair Chromatography of Aromatic Sulfonic Acids (방향족 슬폰산들의 역상 이온쌍 크로마토그래피)

  • Sam-Woo Kang;Hae-Beom Oh;Seung-Seok Lee
    • Journal of the Korean Chemical Society
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    • v.30 no.2
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    • pp.224-230
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    • 1986
  • Dodecyltrimethylammonium bromide (DTAB) was examined as a counter-ion in the separation of aromatic sulfonic acids on alkylmodified silica (ODS) column by reversed-phase ion-pair chromatography. The capacity factor of acids was investigated and separation was attempted. The capacity factor of samples was influenced by the several factors such as a concentration of counter-ion, concentration of methanol, kinds and concentration of electrolyte in mobile phase as well as kinds and position of functional group in samples. Some mixtures of samples were able to be separated under optimum condition.

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Lead optimization of 2-imino-1,3-thiazolines and in vivo antifungal activity against rice blast (I) (2-이미노-1,3-티아졸린 유도체의 최적화 및 벼 도열병에 대한 방제활성 (I))

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Bae, Su-Yeal;Park, Ik-Kyu
    • The Korean Journal of Pesticide Science
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    • v.8 no.3
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    • pp.168-174
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    • 2004
  • In a course of the process for a lead optimization of 2-imino-l,3-thiazolines 1 which show a selective in vivo antifungal activity against rice blast, new compounds 2 in which C-5 was substituted by methyl group of the lead compound were synthesized and tested for the biological activity. Bromination of $\beta$-keto ester 7 followed by the reaction with thiourea and hydrolysis gave 2-imino-5-methyl-l,3-thiazoline carboxylic acid 3. Coupling reactions of 3 with aniline derivatives afforded 17 kinds of the corresponding 2-imino-5-methyl-l,3-thiazoline carboxanilides 2. Their in vivo antifungal activity against rice blast was weaker than that of 1, indicating that the in vivo antifungal activity of 2-imino-l,3-thiazolines was affected by the substituent at C-5. These results would be an important data for the molecular design in the lead optimization process of this series.

Assessment of Methylbromide Exposure Levels in Fumigation Workers on Import and Export Plant (수출입식물 훈증 작업자의 브롬화메틸 노출수준 평가)

  • Jeong, Jee Yeon;Yi, Gwang-Yong;Cho, Sook-Ja;Park, Seung-Hyeon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.1
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    • pp.50-57
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    • 2020
  • Objectives: Methyl bromide is a highly toxic substance that can cause systemic poisoning, neurotoxicity, pulmonary edema. Methyl bromide is a widespread fumigation agent used for import and export quarantine, but there is little data on exposure assessment of workers participating in such fumigation. Therefore, this study aims to investigate the exposure level of methyl bromide among workers and the concentration distribution of methyl bromide in the workplace during fumigation. Methods: For this study, one wood tent and one container fumigation area in Pusan, and one wood tent fumigation area in Incheon were investigated over three months from June 2001. Results: Methyl bromide exposure levels for container fumigation workers were from undetected to 1.86 ppm and from undetected to 2.28 ppm for tent fumigation workers as an 8 hr TWA. After opening the container door, the methyl bromide concentration in the container decreased rapidly over time, but the concentration remained over 1 ppm even after about one hour. The concentrations around the tent during its removal were highly affected by wind, but were detected in a range from undetected to 11.97 ppm. Conclusions: This study confirmed that both container and tent fumigation caused workers to exceed the exposure limit of 1 ppm as an 8 hour TWA. In particular, it could be confirmed that a situation exists in which the worker may be exposed to high concentrations of methyl bromide when opening the container or removing the tent due to the nature of the work. Therefore, it is very important to improve working methods and to wear appropriate personal protective equipment.