• 제목/요약/키워드: Methyl bromide

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Methyl Bromide를 대체하는 훈증 가스의 문화재 재질 안정성 평가 II (The 2nd Stability Appraisement on Cultural Property Material with the Replacing Fumigation Gas of Methyl Bromide II)

  • 강대일
    • 보존과학회지
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    • 제25권4호
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    • pp.465-471
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    • 2009
  • 본 연구에서는 Methyl Bromide를 대체할 15% Ethylene Oxide + 85% HFC 134a, 20% Ethylene Oxide + 80% $CO_2$, 99% Sulfuryl Fluoride + 1% Inert Gas를 이용하여 훈증처리 시, 금속, 안료, 섬유 및 지류시편에 미치는 영향을 관찰한 실험이다. 15% Ethylene Oxide + 85% HFC 134a을 200g/$m^3$, 48시간 훈증 처리 한 결과 Cu 시편은 1차 및 2차 훈증처리 실험 모두 육안으로 식별할 수 있는 평균 3.40, 4.17의 색차값을 나타났다. 그 외의 시편에서는 색차값이 3.0 미만으로 나타났다. 20% Ethylene Oxide + 80% $CO_2$을 150g/$m^3$, 48시간 처리한 1, 2차 훈증처리 모두 전체적으로 실험군의 색차값이 평균 3.0 미만으로 나타났으며 이는 육안으로 식별할 수 없는 미미한 색차이다. 이에 따라 이 연구에 사용된 재질에 비교적 안정적이라고 판단된다. 99% Sulfuryl Fluoride + 1% Inert Gas로 50g/$m^3$, 48시간 처리한 결과, 안료 중 장단 시편은 1, 2차 훈증처리 시 대조군의 색차값과 비교하여 보았을 때 3.0이상 색차값의 변화가 나타났다. 그 외의 시편에서는 색차값이 평균 3.0 미만으로 나타났다.

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Simple Synthesis of Novel 1',4'-Dimethyl Branched Carbovir Analogues

  • Kim, Ai-Hong;Hong, Joon-Hee
    • Bulletin of the Korean Chemical Society
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    • 제26권11호
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    • pp.1767-1770
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    • 2005
  • Novel 1',4'-dimethyl branched carbocyclic nucleosides were synthesized from acetol. The 4'-methyl group was installed via a Claisen rearrangement reaction, and the carbonyl addition of methylmagnesium bromide was used to introduce the 1'-methyl group. The coupling of nucleosidic bases and desilylation was used to produce a series of novel nucleosides.

Synthesis of Novel Carbovir Analogue

  • Kim, Ai-hong;Hong, Joon-Hee
    • Bulletin of the Korean Chemical Society
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    • 제27권7호
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    • pp.976-980
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    • 2006
  • The synthesis of 4'-phenyl and 1'-methyl doubly branched carbocyclic nucleoside was accomplished from 2-hydroxy acetophenone. The 4'-phenyl group was installed via a [3,3]-sigmatropic rearrangement reaction, and the carbonyl addition of methylmagnesium bromide was used to introduce the 1'-methyl group. Cyclization of divinyl 9 was performed using $2^{nd}$ generation Grubbs catalyst. The coupling of cyclopentenol 12$\alpha$ with 6-chloropurine by Mitsunobu reaction and desilylation was used to synthesize the target nucleoside 15.

New Tridentate Ligands with Mixed Donor Atoms for Cu-Based Atom Transfer Radical Polymerization

  • Cho, Hong-Youl;Han, Byung-Hui;Kim, Il;Paik, Hyun-Jong
    • Macromolecular Research
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    • 제14권5호
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    • pp.539-544
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    • 2006
  • 2-Furancarboxaldehyde-2-pyridinylhydrazone (FPH) and 5-methyl-2-furancarboxaldehyde-2-pyridinylhydrazone (MFPH) were synthesized and used as tridentate ligands of copper (I) bromide for the atom transfer radical polymerization of methyl methacrylate (MMA) and styrene. The polymerization of methyl methacrylate achieved high conversion and yielded polymers with a good control of molecular weight and low polydispersity (PDI=1.33). Higher PDI were observed in the polymerization of styrene. Using 1-phenyl ethylbromide (PEBr) and ethyl 2-bromoisobutyrate (EBiB) as model compounds for the polymeric chain ends, the activation rate constants of the new catalytic systems were measured. These results were correlated with the polymerization results and compared with another catalytic system previously reported.

Synthesis of ($\pm$)-Methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-amines

  • Jang, Jin-Hee;Sin, Kwan-Seog;Park, Hae-Il
    • Archives of Pharmacal Research
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    • 제24권6호
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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.

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고진공 상태에서 아닐린과 o-클로로 아닐린 용액중 브롬화갈륨과 브롬화에탄과의 착물형성에 관한 연구 (The Study on Complex of Gallium Bromide with Ethyl Bromide in Aniline and in o-Chloroaniline under High Vacuum)

  • 김영철;김세경;구덕자;임종완
    • 대한화학회지
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    • 제35권5호
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    • pp.480-486
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    • 1991
  • 아닐린 및 o-클로로아닐린 용액내에서 브롬화에탄의 용해도를 5, 1.5$^{\circ}$ 및 25$^{\circ}$C에서 브롬화칼륨이 존재할 때와 존재하지 않을 때의 두 경우에 대하여 각각 측정하여 보았다. 브롬화칼륨이 존재하지 않을 때에 o-클로로아닐린에서 브롬화에탄의 용해도가 아닐린에서 보다 크다. 이것은 브롬화에탄과 o-클로로아닐린의 상호작용이 아닐린보다 더 강하다는 것을 나타낸다. 그리고 브롬화칼륨이 존재할 경우에는 용액내에서 브롬화에탄과 브롬화칼륨이 불안정한 착물이 생성된다. 이 착물을 여러 경우로 가정하여 계산하여 본 결과 1:1 착물일 때, 불안정 상수 K값이 비교적 일정한 값을 나타내었다. 그러므로 1:1 착물 $C_2H_5Br[\cdot}GaBr_3$가 형성됨을 알았으며, 이 착물은 용액내에서 다음 평형식에 의해서 이루어진다고 본다. $C_2H_5Br{\cdot}GaBr_3\;{\rightleftharpoons}\;C_2H_5Br+1/2Ga_2Br_6$ 브롬화칼륨과 브롬화에탄의 착물의 불안정도를 이와 대응하는 브롬화메탄과 비교하여 보았다. 또한 이 착물의 해리에 대한 엔탈피, 자유에너지 및 엔트로피 변화도 산출하였다.

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Solid Wood Packaging Materials for International Trade

  • Han, Jong-Koo
    • 한국포장학회지
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    • 제17권2호
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    • pp.29-31
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    • 2011
  • Hazards associated with use of wood packaging in international trade were addressed with regulations enforced. Measures to avoid spreading of pest in the trade were discussed in terms of current status and future availability.

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Evaluation on Biological Sensitivity of Three Fumigants Used for Conservation of Wooden Cultural Property

  • Kim, Si Hyun;Kim, Dae Woon;Lee, Hyun Ju;Lee, Byung Ho;Kim, Bong Su;Chung, Yong Jae
    • Journal of the Korean Wood Science and Technology
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    • 제44권4호
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    • pp.526-538
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    • 2016
  • Fumigants are used worldwide for control of biological agents that damage wooden cultural property. To establish a policy for fumigant use, biological evaluation of insects and microorganisms considering many factors is required. This study was performed to evaluate biological sensitivity and wood penetration of three fumigants applied for control of biological agents that damage wooden cultural properties in Korea. Among these, methyl bromide and ethylene oxide can control insects and fungi when exposed directly. However, they were unable to completely control biological agents within deeper parts of wood. Ethanedinitrile, which was developed as an alternative fumigant, exhibited outstanding wood penetration and biocidal efficacy. Further research involving various environmental conditions is warranted.

수입원목의 본선훈증소독에 관한 연구 (Study on Shipboard Fumigation of the Imported Logs)

  • 유기열;정양원;이명호;제진원
    • 한국응용곤충학회지
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    • 제23권1호
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    • pp.37-41
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    • 1984
  • 선창내 온도가 $10\~20^{\circ}C$에서 $1m^3$당 메칠브로마이드 25g을 투약하여 24시간 훈증소독하면 채집된 원대부착해충과 쌀바구미는 $100\%$죽으며 직경 30cm 회전속도 1,800rpm 이상의 교반기 2태를 설치하고 DT적에 의하여 계산한 37.5g을 투약한 후 16시간 훈증소독을 하여도 24시간 처리와 동일한 살충효과를 얻었다. 가스농도가 균일화되는 데는 교반기를 사용하지 않으면 $4\~6$시간 걸리고 교반기를 사용한 경우는 $1\~3$시간으로 단축되었다.

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One-pot Four Component Reaction of Unsymmetrical 1-Methylbarbituric Acid with BrCN and Various Aldehydes in the Presence of Et3N and/or Pyridine

  • Jalilzadeh, Mohammad;Pesyan, Nader Noroozi
    • 대한화학회지
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    • 제55권6호
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    • pp.940-951
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    • 2011
  • Reaction of 1-methylpyrimidine-(1H,3H,5H)-2,4,6-trione (1-MBA 1) as an unsymmetrical barbituric acid with cyanogen bromide and various aldehydes in the presence of triethylamine and/or pyridine afforded diastereomeric mixtures of new class of heterocyclic stable 5-aryl-1,1'-dimethyl- and 5-aryl-3,1'-dimethyl-1H,1'H-spiro[furo[2,3-d]pyrimidine-6,5'-pyrimidine]2,2',4,4',6'(3H,3'H,5H)-pentaones which are dimeric forms of 1-methyl barbiturate at the range of $0^{\circ}C$ to room temperature. In the reaction of some aldehydes with 1-MBA and BrCN were afforded a mixture of diastereomers. Another two aldehydes such as 4-cyano- and 2-hydroxybenzaldehydes gave exclusively two diastereomers in which binded to the salt of triethylammonium hydrobromide by intermolecular H-bond in ratio of 1:1. 4-Hydroxybenzaldehyde and 2-pyridinecarbaldehyde gave exclusively one diastereomer under the same condition. Aldehydes possessing strong electron-donor were produced exclusively two geometric isomers of Knoevenagel adduct (E- and Z-isomers). The structures of compounds were deduced by $^1H$ NMR, $^{13}C$ NMR and FT-IR spectroscopy. Mechanism of the formation is discussed.