• Title/Summary/Keyword: N,N-Dimethylformamide

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Halolactonization reaction using N-haloimides

  • Cook, Chae-Ho;Cho, Youn-Sang;Jew, Sang-sup;Suh, Young-Guh;Kang, Eung-Ku
    • Archives of Pharmacal Research
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    • v.6 no.1
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    • pp.45-53
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    • 1983
  • Novel halactolactonizations using NBS (2), NIS(3), and NSP(4) in dry DMF were found to be the most reasonable and efficient procedures. The participation of X as the cylization initiator could be clarly rationalized by experimental results and the regioselectivities of formed halolactones were reasonably elucidated by weakly bridged carbonium ion intermediate.

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Measurement and Modeling of Bubble Points for Binary Mixtures of Carbon Dioxide and N,N-Dimethylformamide (이산화탄소와 디메틸포름아마이드 혼합물의 기포점 측정 및 모델링)

  • Jung, Joon-Young;Lee, Byung-Chul
    • Clean Technology
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    • v.17 no.1
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    • pp.19-24
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    • 2011
  • The bubble point pressures of binary mixtures of carbon dioxide ($CO_2$) and N,N-dimethylformamide (DMF) were measured by using a high-pressure experimental apparatus equipped with a variable-volume view cell, at various $CO_2$ compositions in the range of temperatures above the critical temperature of $CO_2$ and below the critical temperature of DMF. The experimental bubble point pressure data were correlated with the Peng-Robinson equation of state (PR-EOS) to estimate the corresponding dew point compositions at equilibrium with the bubble point compositions. The experimentally measured bubble point pressures gave good agreement with those calculated by the PR-EOS. The variable-volume view cell equipment was verified to be an easy and quick way to measure the bubble point pressures of high-pressure compressible fluid mixtures.

Intermolecular Hydrogen Bonding and Vibrational Analysis of N,N-Dimethylformamide Hexamer Cluster

  • Park, Sun-Kyung;Min, Kyung-Chul;Lee, Choong-Keun;Hong, Soon-Kang;Kim, Yun-Soo;Lee, Nam-Soo
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2595-2602
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    • 2009
  • Hexamer cluster of N,N-dimethylformamide(DMF) based on the crystal structure was investigated for the equilibrium structure, the stabilization energies, and the vibrational properties in the density functional force field. The geometry (point group $C_i$) of fully optimized hexamer clustered DMF shows quite close similarity to the crystal structure weakly intermolecular hydrogen bonded each other. Stretching force constants for intermolecular hydrogen bonded methyl and formyl hydrogen atoms with nearby oxygen atom, methyl C–H${\cdots}$O and formyl C–H${\cdots}$O, were obtained in 0.055 $\sim$ 0.11 and $\sim$ 0.081 mdyn/$\AA$, respectively. In-plane bending force constants for hydrogen bonded methyl hydrogen atoms were in 0.25 $\sim$ 0.33, and for formyl hydrogen $\sim$ 0.55 mdynÅ. Torsion force constants through hydrogen bonding for methyl hydrogen atoms were in 0.038 $\sim$ 0.089, and for formyl hydrogen atom $\sim$ 0.095 mdynÅ. Calculated Raman and infrared spectral features of single and hexamer cluster represent well the experimental spectra of DMF obtained in the liquid state. Noncoincidence between IR and Raman frequency positions of stretching C=O, formyl C–H and other several modes was interpreted in terms of the intermolecular vibrational coupling in the condensed phase.

Concentrations of N,N-dimethylformamide in Polyurethane Gloves and Risk Assessment for Dermal Exposures (폴리우레탄 코팅장갑내의 DMF 함량 및 피부노출에 대한 평가)

  • Park, Hae Dong;Ro, Jiwon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.32 no.2
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    • pp.102-110
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    • 2022
  • Objectives: The purpose of this study is to analyze the content of N,N-dimethylformamide(DMF) in polyurethane coated gloves(PU-gloves) and to assess the dermal exposure generated by wearing them. Methods: We analyzed the concentrations of DMF in 12 gloves by EN16778 standard. The samples cut into pieces of about 10 by 10 mm and extracted with methanol in flask in an ultrasonic bath at 70℃. An aliquot of the extract is analyzed with GC-MS. The dose of dermal exposure was calculated by ECETOC TRA consumer 3.1 and compared with derived no effect level(DNEL) for systemic effects due to long term exposure by workers. The extracted amount of DMF by saline solution was compared with that by EN16778 standard. Results: The mean concentration of DMF in PU-gloves was 1,377 mg/kg(range 13~3,948 mg/kg). The concentration of DMF showed significantly differences by packing type, manufacturer, and price(p<0.05). The dose of dermal exposure was 0.0007~0.572 mg/kg body weight/day when the DMF content was 10~4,000 mg/kg. The DMF extracted by saline solution was around 11% for 8 hours. Conclusions: The risk of dermal exposure due to the residual DMF in the PU-gloves was not signifiant. But, the limit of 1,000 mg/kg in PU-gloves can be recommended for international standard and trading systems.

Recrystallization of RDX High Energy Material Using N,N-Dimethylformamide Solvent and Supercritical $CO_2$ Antisolvent (디메틸포름아마이드 용매와 초임계 이산화탄소 역용매를 사용한 RDX 고에너지 물질의 재결정)

  • Kim, Chang-Ki;Lee, Byung-Chul;Lee, Youn-Woo;Kim, Hyoun-Soo
    • Clean Technology
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    • v.15 no.4
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    • pp.233-238
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    • 2009
  • Supercritical fluid processes have gained great attention as a new and environmentally-benign method of preparing the microparticles of energetic materials like explosives and propellants. In this work, RDX (cyclotrimethylenetrinitramine) was selected as a target explosive. The microparticle formation of RDX using supercritical anti-solvent (SAS) recrystallization process was performed and the effect of operating variables on the size and morphology of prepared particles was observed. N,N-Dimethylformamide was used as organic solvent for dissolving the RDX. The size of the RDX particles decreased remarkably up to less than $10\;{\mu}m$ by SAS recrystallization. In the range of operating conditions of the SAS process studied in this work, the finest RDX particles were obtained at 313.15K, 150 bar, and 15wt% RDX concentration in feed solution.