• Title/Summary/Keyword: Formamide,

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Reaction of Organic Halogen Compounds with Potassium Fluoride. (Ⅲ) Fluorination of Aromatic vic-dihalides (有機할로겐化合物과 KF의 反應 (第3報) 芳香族이웃디할라이드의 弗化反應)

  • You Sun Kim;Ki Soo Kim
    • Journal of the Korean Chemical Society
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    • v.13 no.1
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    • pp.68-74
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    • 1969
  • Flourination of Ethyl, ${\alpha},{\beta$}-dichloro-${\beta$}-phenyl propionate, Ethyl ${\alpha},{\beta$}-dibromo ${\beta$}-phenyl propionate, Ethyl ${\alpha},{\beta$}-dichloro ${\beta$}-(p-chloro-phenyl) propionate, and dibromostyrene by potassium fluoride were investigated in presence of dimethyl formamide, diethylene glycol, and diethylene glycol monomethyl-ether. The reactivity of these organic halogen esters and hydrocarbons towards potassium fluoride was checked further by means of radioactive fluorine-18. tracer. Generally, the reaction gave monofluoride together with dehalogenated olefin. The formation of olefine was increased when the reaction was done at high reaction temperature in presence of diethylene glycol, whereas the lower reaction temperature in presence of diethyleneglycol monomethyl ether favored the formation of mono fluoride in a good yield. The procedures and methods of the identification of monofluorides were described and the feasibility of this reaction of fluorine containing ester including the F-18 labelled compounds was discussed.

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The Effects of CD-product Specificity upon the Enzyme [CGTase] Reaction Condition (효소 [CGTase : Cyclodextrin glucanotransferase]의 반응 조건이 산물 [CD : Cyclodextrin]의 특이성에 미치는 영향)

  • 최희욱;홍순강
    • KSBB Journal
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    • v.19 no.2
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    • pp.164-167
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    • 2004
  • Cyclodextrin glucanotransferase (EC 2.4.1.19, abbreviated as CGTase) is one of the most applied industrial enzymes that produces cyclodextrins from starch and related ${\alpha}$-1,4-glucans by intramolecular transglycosylation reaction upon Ca$\^$2+/ dependent manner. The reaction of CLEC, ${\alpha}$-CGTases from Bacillus macerans with the soluble starch as a substrate reveals that the surfactants (SDS, N-octyl-${\beta}$-D-glucoside) significantly affect not only the overall products of CDs but also their selectivity. The surfactants (SDS, Lubrol PX) trigger the increase of ${\alpha}$-CD production, but Triton x-100 and Tween 80 suppress ${\alpha}$-CD specificity. Organic solvents (dimethyl sulfoxide, formamide, 2-methyl-2,4-pentandiol, and ethylene glycol) also cause changes of total product and product selectivity.

The Rheological Properties of Poly(acrylonitrile)/Cellulose Acetate Blend Solutions in N,N-Dimethyl Formamide (폴리아크릴로니트릴/셀룰로오스 아세테이트/N,N-디메틸포름아미드 용액의 유연학적 특성)

  • Park, Seung-Han;Song, In-Kyu;Kim, Byoung-Chul
    • Polymer(Korea)
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    • v.33 no.4
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    • pp.384-388
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    • 2009
  • The rheological properties of poly (acrylonitrile) (PAN) and cellulose acetate (CA) blend solutions in N,N-dimethyl formamide (DMF) were investigated in terms of temperature and blend composition. The solutions exhibited a very characteristic rheological behavior with variation of temperature. 8 wt% solution showed an increase of viscosity and a decrease of loss tangent as temperature was increased over the temperature range of 20 and $60^{\circ}C$. At $20^{\circ}C$ the physical properties of the solutions exhibited dependence on the blend composition. At 40 and $60^{\circ}C$, however, the effects of blend ratio on the physical properties notably diminished. The longer relaxation time at higher temperature indicated that the formation of physical structures resulting from intermolecular interactions was promoted with increasing temperature. The odd rheological responses were further elucidated by measuring of the physical properties of dilute solutions. The intrinsic viscosity of the solutions suggested that the coiled chain dimension was reduced with increasing temperature.

Preparation of Ultra-Low Thermal Expansion L$i_2$O-A$l_2$$O_3$-Si$O_2$ Glass-Ceramics by Sol-gel Technique (졸-겔 방법에 의한 $Li_2O-Al_2O_3-SiO_2$계 저열팽상성 결정화유리의 제조)

  • Yang, Jung-Sik;Kim, Jong-Beom;Yang, Jung-Sik
    • Korean Journal of Materials Research
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    • v.3 no.3
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    • pp.207-214
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    • 1993
  • Glass-ceramic monoliths with an ultra-low thermal expansion coefficient have been synthesized by the sol-gel technique using metal alkoxides as starting materials and dimethyl formamide as a drying control chemical additive. The ternary gels: $Li_2O\cdot Al_2O_3\cdot 2, 4 or $6SiO_2$ were obtained by hydrolysis and polycondensation reactions of metal alkoxides of silicon, aluminum and lithium. To produce cylindrical crack-free gel monoliths, excess water was used to the starting solutions and drying rates were controlled precisely to prevent cracking. In conversion process ,${\beta}$-eucryptite, $Li_2O\cdot Al_2O_3\cdot 3SiO_2$ and P-spodumene with ,${\beta}$-quartz solid solution phase were obtained by heating at the range of 750 ~$1000^{\circ}C$. Above $800^{\circ}C$, the ,${\beta}$-spodumene phase increased while ,${\beta}$-eucryptite phase decreased. The thermal expansion coefficient of the crystallized specimens were -15~ $+5{\times}{10^{-7}}/{\circ}C$ over the temperature range from room temperature to $600^{\circ}C$.

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Comparison of Phytoplankton Chlorophyll-$\alpha$ Extracted with Different Solvents

  • Lee, Yun-Kyoung;Shin, Myoung-Sun;Jung, Yu-Kyong;Jang, Chang-Won;Kim, Bom-Chul
    • Korean Journal of Ecology and Environment
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    • v.41 no.4
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    • pp.485-489
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    • 2008
  • Algal chlorophyll-$\alpha$ is commonly determined by spectro-photometric method using 90% acetone as solvents. However, acetone has low extraction efficiency without grinding filters, and DMF (dimethyl formamide) was tested for the compatibility with acetone. Chlorophyll-$\alpha$ concentration was determined for samples from 5 reservoirs of different trophic states and phytoplankton composition, using acetone extraction with grinding and DMF without grinding. Chlorophyll-$\alpha$ measured by DMF and Acetone did not show a significant difference when using trichromatic method of UNESCO and Lorenzen, and therefore, DMF can substitute acetone. But when acidification method was applied, they showed significant difference of 8%. It can be concluded that DMF can extract chlorophylls more effectively without grinding and it can be a better alternative for the standard extraction solvent.

Synthesis, Reactions and Antimicrobial Activity of 2-Amino-4-(8-quinolinol-5-yl)-1-(p-tolyl)-pyrrole-3-carbonitrile

  • Abdel-Mohsen, Shawkat A.
    • Bulletin of the Korean Chemical Society
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    • v.26 no.5
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    • pp.719-728
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    • 2005
  • A novel 2-amino-4-(8-quinolinol-5-yl)-1- (p-tolyl)-pyrrole-3-cabonitrile (2) was obtained by the reaction of 2-[2-bromo-1-(8-hydroxyquinolin-5-yl)-ethylidene]-malononitrile (1) with p-toluidene. The new synthon compound (2) could be annelated to the corresponding pyrrolo[2,3-d]pyrimidines (4, 6, 7, 26-28), triazolo[1,5-c]pyrrolo[3,2-e]pyrimidines (10, 29, 30), pyrrolo[2,3-c]pyrazoles (11-15), pyrrolo[1,2-a]pyrrolo[3,2-e] pyrimidine (17) and imidazo[1,2-c]pyrrolo[3,2-e]pyrimidines (18-25) via the reaction with some reagents such as acetic anhydride, formamide, triethyl orthoformate, hydrazine hydrate, hydroxylamine, ethylenediamine, carbon disulfide and phosphorus oxychloride. Chemical and spectroscopic evidences for the structures of these compounds are presented. The antifungal and antibacterial activity of the newly synthesized comounds were evaluated.

Chemical synthesis of processable conducting polyaniline derivative with free amine functional groups

  • Kar, Pradip
    • Advances in materials Research
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    • v.3 no.2
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    • pp.117-128
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    • 2014
  • Processable conducting polyaniline derivative with free amine functional groups was successfully synthesized from the monomer o-phenylenediamine in aqueous hydrochloric acid medium using ammonium persulfate as an oxidative initiator. The synthesized poly(o-phenylenediamine) (PoPD) in critical condition was found to be completely soluble in common organic solvents like dimethyl sulfoxide, N,N-dimethyl formamide etc. From the intrinsic viscosity measurement, the optimum condition for the polymerization was established. The polymer was characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy ($^1HNMR$) and thermogravimetric (TGA) analyses. The weight average molecular weights of the synthesized polymers were determined by the dynamic light scattering (DLS) method. From the spectroscopic analysis the structure was found to resemble that of polyaniline derivative with free amine functional groups attached to ortho/meta position in the phenyl ring. However, very little ladder unit was also present with in the polymer chain. The moderate thermal stability of the synthesized polymer could be found from the TGA analysis. The average DC conductivity of $2.8{\times}10^{-4}S/cm$ was observed for the synthesized polymer pellet after doping with hydrochloric acid.

Structure and Properties of Polymer Infiltrated Alumina Thick film via Inkjet Printing Process (잉크젯 프린팅 공정에 의한 유전체 후막의 제조 및 특성)

  • Jang, Hun-Woo;Koo, Eun-Hae;Kim, Ji-Hoon;Kim, Hyo-Tae;Yoon, Young-Joon;Hwang, Hae-Jin;Kim, Jong-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.4
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    • pp.297-302
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    • 2009
  • We have successfully fabricated the alumina thick films using inkjet printing processes without a high temperature sintering process. Alumina suspension as dielectric ink was formulated by combining nano-sized alumina powders with an anionic polymer dispersant in formamide/water as co-solvent. The thickness of the printed alumina thick film was measured at around 5 um by field emission scanning electron microscope. The calculated packing density of 68.5 % from the printed alumina thick film was much higher than the same films fabricated by conventional casting or dip coating processes. Q factor of the dielectrics thick film infiltrated with cyanate ester resin was evaluated by impedance analyzer.

Preparation and Permeation Characteristics of Finely Porous Ultrafiltration Membranes by Phase Inversion Method (상전환법에 의한 미세다공성 한외여과막의 제조 및 투과특성)

  • 홍영기;배기서
    • Textile Coloration and Finishing
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    • v.15 no.2
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    • pp.68-75
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    • 2003
  • In this work, ultrafiltration(UF) membranes were prepared using polyethersulfone(PES). The polymer was dissolved in various solvent, such as N, N-dimethyl formamide(DMF), N,-dimethyl acetamide (DMAc), N,N-dimethyl sulfoxide(DMSO) and N-methyl-2- pynolidone(NMP). Each polymer solution was casted on the glass plate, and immersed into non-solvent bath. In this way finely porous UF membranes were prepared by phase inversion method. The cross sectional structure of PES membrane was asymmetric which was consist of sponge-like sublayer, finger-like toplayer, and active skin layer. From the solute rejection experiments, the molecular weight cut off of the prepared membrane in various solvent was evaluated 10,000 for DMF, 30,000 for DMAc, 50,000 for DMSO, and 10,000 for NMP respectively.

Synthesis of Blue-green Naphthoxy, Chloro Derivative Zinc-phthalocyanines with LCD Requirements

  • Kumar, Rangaraju Satish;Min, Kyeong Su;Son, Young-A
    • Textile Coloration and Finishing
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    • v.30 no.3
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    • pp.159-167
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    • 2018
  • Here we designed and synthesized new zinc phthalocyanines and structures were fully confirmed by spectral and elemental analysis. All phthalocyanines have a very good solubility in industrial solvents like chloroform, dichloromethane, dimethyl sulfoxide, N,N-dimethyl formamide, propylene glycol monomethyl ether acetate (PGMEA), acetone, tetrahydrofuran and acetonitrile. UV-Visible absorption and transmittance in PGMEA showed that these dyes have suitable spectral properties for LCD color filters. By Triton X surfactant study, we confirmed that these dyes are not showing any aggregation in PGMEA. We dissolved the all phthalocyanines in LCD fabricating solvent (PGMEA), and all phthalocyanines showed more than 8 wt% of solubility. Finally, all of these results concluded that PCK1, PCK2 and PCK3 are fit for LCD green color filter.