• 제목/요약/키워드: N,N-Dimethylformamide

검색결과 196건 처리시간 0.028초

크롬(VI)-퀴놀린 화합물에 의한 알코올류의 산화반응에 대한 반응속도론적 연구 (Kinetic Study on the Oxidation Reaction of Alcohols by Cr(VI)-Quinoline Compound)

  • 박영조;김수종
    • 융합정보논문지
    • /
    • 제11권9호
    • /
    • pp.109-114
    • /
    • 2021
  • 유기공업 화학에서 알코올류의 산화제에 대해 연구가 많이 진행 되고 있으며, 그중에서도 크롬(VI)-계열의 시약들이 산화제로 널리 이용되어 왔다. 그리고 일차알코올을 알데히드로만 산화시키는 산화제와 메카니즘 규명이 필요하게 되었다. 이러한 연구의 일환으로 본 연구에서는 퀴놀린과 chromium(VI) trioxide을 반응시켜 크롬(VI)-퀴놀린 화합물[(C9H7NH)2Cr2O7]을 합성하여, FT-IR 및 원소분석에서 구조를 확인하였다. 여러 가지 유기용매를 사용하여 크롬(VI)-퀴놀린 화합물에 의한 벤질 알코올의 산화반응은 유전상수 값이 큰 유기용매인 N,N'-dimethylformamide에서 높은 산화반응성을 보였다. N,N'-dimethylformamide 용매를 사용하여 크롬(VI)-퀴놀린 화합물은 치환 벤질 알코올류를 효율적으로 산화시켰고, Hammett 반응상수(ρ)=-0.69(303 K) 이였다. 본 실험에서 알코올의 산화반응 과정은 chromate ester 형성과정과, 속도결정단계에서 수소화 전이가 일어나는 반응경로임을 알 수 있었다. 결과적으로 크롬(VI)-퀴놀린 화합물은 벤질알코올, 알릴알코올, 일차알코올 및 이차알코올류를 알데히드나 케톤으로 전환시키는 효율적인 산화제로, 이차알코올류 존재 하에서 벤질알코올, 알릴알코올, 일차알코올의 선택적인 산화제로 사용할 수 있다.

A New Combined Source of "CN" from N,N-Dimethylformamide and Ammonia in the Palladium-Catalyzed Cyanation of Aryl C-H Bonds

  • Choi, Ji-Ho;Kim, Jin-Ho;Chang, Suk-Bok
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
    • /
    • pp.207-207
    • /
    • 2011
  • Aromatic nitriles possess versatile utilities and are indispensible not only in organic synthesis but also in chemical industry. In fact, the nitrile group is an important precursor for various functional groups such as aldehydes, amines, amidines, tetrazoles, amides, and their carboxyl derivatives. Representative methods for the preparation of organonitriles with cyanide-containing reagents are the Sandmeyer and Rosenmund-von Braun reactions. Recently, a catalytic route to aryl nitriles has been reported on the basis of the chelation-assisted C-H bond activation or metal-catalyzed cyanation of haloarenes. In those cyanation protocols, the "CN" unit is provided from metal-bound precursors of MCN (M=Cu, K, Na, Zn), TMSCN, or K3Fe(CN)6. Additionally, it can be generated in situ from nitromethane or acetone cyanohydrin. Herein, we report the first example of generating "CN" from two different, readily available precursors, ammonia and N,N-dimethylformamide (DMF). In addition, its synthetic utility is demonstrated through the Pd-catalyzed cyanation of arene C-H bonds.

  • PDF

Static Dielectric Constant and Relaxation Time for the Binary Mixture of Water, Ethanol, N. N-Dimethylformamide, Dimethylsulphoxide, and N, M-Dimethylacetamide with 20Hethoxyethanol

  • Ajay Chaudgari;N. M. More;S. C. Mehrotra
    • Bulletin of the Korean Chemical Society
    • /
    • 제22권4호
    • /
    • pp.357-361
    • /
    • 2001
  • Frequency spectra of the complex permittivity of 2-methoxyethanol (2-ME) with water, ethanol, dimethylsulphoxide (DMSO), N,N-dimethylformamide (DMF) and N,N-dimethylacatamide (DMA) have been determined over the frequency range of 10 MHz to 20 GHz at 25 $^{\circ}C$, using the Time domain reflectometry method, for 11 concentrations for each system. The static dielectric constant, dielectric constant at microwave frequency, relaxation time, excess dielectric parameters, and Kirkwood correlation factor have been determined. The relaxation in these systems within the frequency range can be described by a single relaxation time constant, using the Debye model. The parameters show a systematic change with the concentration.

Novel Bromolactonization Using N-bromophthalimide

  • Cook, Chae-Ho;Kang, Eung-Ku
    • Archives of Pharmacal Research
    • /
    • 제4권2호
    • /
    • pp.137-139
    • /
    • 1981
  • Reaction of olefinic acids with N-bromophthalimide in dry N, N-dimethylf-ormamide at room temperature gives bromolactones in good yields.

  • PDF

$CCl_4$속에서 Thioacetamide의 N-C(S) 부자유회전에 미치는 몇가지 Amide의 영향 (Effect of Some Amides on the Hindered Rotation of N-C(S) Bond of Thioacetamide in $CCl_4$)

  • 노성구;최영상;윤창주
    • 대한화학회지
    • /
    • 제31권6호
    • /
    • pp.486-490
    • /
    • 1987
  • $CCl_4$속에서 티오아세트산아미드(TA)와 몇가지 아미드(N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA) and N,N-dimethylpropionamide (DMP)) 사이의 수소결합이 TA의 N-C(S) 결합 주위의 부자유 회전에 미치는 영향을 nmr 분광학적인 방법으로 연구하였다. $CCl_4$분율이 증가할 때 TA의 $NH_2$기의 양성자 nmr 스펙트럼은 이중선으로 뚜렷하게 분리되었으며, 그 정도는 DMF < DMA < DMP순으로 증가하였다. 이런 현상을 TA와 아미드사이의 분자간 수소결합으로 설명하였다.

  • PDF

Clinical Outcomes of Occupational Exposure to N,N-Dimethylformamide: Perspectives from Experimental Toxicology

  • Kim, Tae-Hyun;Kim, Sang-Geon
    • Safety and Health at Work
    • /
    • 제2권2호
    • /
    • pp.97-104
    • /
    • 2011
  • N,N-Dimethylformamide (DMF) is globally used as an organic solvent in the production of synthetic leather and resins because of its low volatility, making it an attractive industrial material. Despite its excellent property as a chemical solvent, utilization of DMF is somewhat controversial nowadays due to its hazardous effects on exposed workers in work places. Many toxification cases are being reported globally and the number of cases of liver damage is still increasing in developing countries. On account of this, a series of epidemiologic surveys are being conducted to understand the degrees of liver damage caused by DMF exposure. Furthermore, many investigations have been performed to clarify the mechanism of DMF-induced liver toxicity using both human and experimental animal models. This review summarizes the current occupational cases reported on liver damage from workers exposed to DMF in industrial work places and the research results that account for DMF-induced liver failure and possible carcinogenesis. The findings reviewed here show the synergistic toxicity of DMF exposure with other toxicants, which might occur through complicated but distinct mechanisms, which may extend our knowledge for establishing risk assessments of DMF exposure in industrial work places.

섬유코팅업종사 근로자에서 디메틸포름아미드의 폭로에 의한 생물학적 모니터링에 영향을 미치는 인자 (Influencing Factors that Affect the Biological Monitoring of Workers Exposed to N,N-Dimethylformamide in Textile Coating Factories)

  • 정인성;김종환;최상국;배종연;이미영
    • Journal of Preventive Medicine and Public Health
    • /
    • 제39권2호
    • /
    • pp.171-176
    • /
    • 2006
  • Objectives : The objective of this study is to assess the factors influencing biological monitoring of textile coating factory workers exposed to N,N-dimethylformamide(DMF). Methods : We studied 35 workers who were occupationally exposed to DMF from 9 textile coating factories. The study was carried out in two phases; summer and winter. While air concentration of DMF, temperature and humidity were assessed in order to monitor the atmospheric conditions, biological monitoring was done to determine the internal dose by analyzing the N-methylformamide(NMF) collected from urine at the beginning and end of the shift. Questionnaires and medical surveillance were also obtained during the two phases. Results : Median air concentrations of DMF in winter and summer were 1.85 ppm and 2.78 ppm respectively. Also the difference between the urinary NMF concentration at the beginning and end of the shift $({\Delta}NMF)$ was always significant in each season (P < 0.001). The correlations between log DMF in air, log end-of-shift urinary NMF (r=0.555, P < 0.001) and log ${\Delta}NMF$ (r = 0.444, P < 0.001) was statistically significant in summer. The temperature, humidity, a shift system and different styles of clothing worn were significantly different during the two phases. In a multivariate analysis, temperature and the concentration of DMF in the air were the main factors influencing biological monitoring of textile coating factory workers. Conclusions : Concerning more comprehensive prevention measures to reduce exposure for those workers occupationally exposed to DMF, dermal exposure conditions such as temperature and humidity together with the air concentration of DMF should be assessed and biological monitoring is necessary to reduce adverse health effects, especially during the summer.

N,N'-Oxalylbis(salicylaldehyde hydrazone)을 이용한 구리의 분광광도법 정량 (Spectrophotometric Determination of Copper with N,N'-Oxalylbis(salicylaldehyde hydrazone)

  • 김용남;최규성;이익희;박기민;정유진
    • 대한화학회지
    • /
    • 제36권1호
    • /
    • pp.95-99
    • /
    • 1992
  • N,N'-Oxalylbis(salicylaldehyde hydrazone)을 발색시약으로 하여 분광광도법에 의한 구리의 정량법을 개발하였다. 정량은 60% dimethylformamide 수용액(pH2)에서의 구리착물의 흡광도를 422nm의 파장에서 측정함으로써 수행되었다. 구리의 농도가 0.4${\sim}$1.8 ${\mu}$g/ml인 범위에서 정량이 가능하였으며 이 방법을 합성시료 및 합금시료의 분석에 적용하였다.

  • PDF

Thermally Crosslinkable Second-Order Nonlinear Optical Polymer Using Pentaerythritol tetrakis(2-mercaptoacetate) as Crosslinker

  • 한관수;심상연;이용석;장웅상;김낙중
    • Bulletin of the Korean Chemical Society
    • /
    • 제19권11호
    • /
    • pp.1168-1171
    • /
    • 1998
  • Two kinds of second-order nonlinear optical copolymers were prepared by the copolymerization of the vinyl monomers containing NLO chromophore, methacrylic acid, and methyl methacrylate or butyl methacrylate. Glass transition temperatures (Tg of copolymers were around 130 ℃. The copolymers were soluble in common organic solvents such as tetrahydrofuran (THF), cyclohexanone, and N,N-dimethylformamide (DMF). The crosslinked copolymer was obtained by thermal treatment using pentaerythritol tetrakis(2-mercaptoacetate) as a crosslinker and became insoluble in tetrahydrofuran (THF) and N,N-dimethylformamide (DMF). Poling was carried out at 120 ℃ for 20 min and identified with UV-Vis spectroscopy. Electro-optic coefficient (r33) measurement showed a value of 35 pm/V for polymer 2 at 633 nm. Temporal stability of copolymers was improved owing to the crosslinked network, which was successfully obtained at 170 ℃ for 30 min after poling.