• 제목/요약/키워드: secondary reaction

검색결과 806건 처리시간 0.026초

Formation of Nitrosamines from Sodium Nitroprusside and Physiological Amines

  • Park, Jeen-Woo
    • Archives of Pharmacal Research
    • /
    • 제12권4호
    • /
    • pp.239-242
    • /
    • 1989
  • Several physiological components containing a secondary amino group were capable of reacting sodium nitroprusside to form potentially carcinogenic nitrosamines under physiological conditions (pH 7.3, 37). In each case the products were identical to those produced upon reaction with nitrous acid at much lower pH values. Reaction rates measured with proline were shown to reflect a first order dependence on both amine and nitroprusside concentrations. The strong influences of pH on the reactions of sodium nitro prusside with amines were also observed. These results show sodium nitroprusside could be a very potent nitrosation agent under physiological conditions.

  • PDF

Reaction of Drugs with Sodium Nitroprusside as a Source of Nitrosamines

  • Park, Jeen-Woo;Gary E. Means
    • Archives of Pharmacal Research
    • /
    • 제14권2호
    • /
    • pp.118-123
    • /
    • 1991
  • Potentially dangerous nitrosamines have been shown to result from the reaction of sodium nitrogusside with several drugs under physiological conditions (pH 7.3 and $37^\circ{C})$. In each case the products were identical to those produced upon reaction with nitrous acid at much lower pH values. Reaction rates were shown to reflect a first order dependence on both amine and nitroprusside concentrations and to increase at higher pH values, approximately in proportion to concentrations of unprotonated amine. Fast reactions of sodium nitroprusside with reduced glutathione, cysteine, and ascorbate suppress but do not prevent the conversion of amines into N-nitrosamines. These results show sodium nitroprusside to be very potent nitrosating agent under physiological conditions and suggested nitrosamines may be formed during its normal pharmacological administration.

  • PDF

탄산마그네슘의 제조연구 II 탄산마그네슘의 전자현미경적 고찰 (Studies on Synthesis of Magnesium Carbonate. II. Electronmicroscopic Shape of Magnesium Carbonate)

  • 이계주;송철;성낙원;안영필
    • 약학회지
    • /
    • 제15권1호
    • /
    • pp.32-40
    • /
    • 1971
  • Optimum reactons for the preparation of extra-light magnesium carbonate from magnesium chloride and sodium carbonate solutions were found by observing the difference of crystalline shapes under an electromicroscope. Reaction temperature the and washing temperature were main factors affecting the crystalline shapes, and drying temperature was found to be of secondary importance. Optimum temperatures for reaction and washing ranged from $20^{\circ}C$ to $30^{\circ}C$ and the temperature over $40^{\circ}C$ should be avoided for the reaction and washing. It was found that the higher the drying temperature, the lighter the crsytal of the produced magnesium carbonate. Reaction time, molar ratio (Mg$^{2+}/CO_{3}^{2-}$ ) and the concentrations of magnesium chloride and sodium carbonate solutions have only a slight effect on the form of the product.

  • PDF

Kinetics and Mechanism of the Anilinolysis of Aryl Ethyl Isothiocyanophosphates in Acetonitrile

  • Barai, Hasi Rani;Adhikary, Keshab Kumar;Lee, Hai Whang
    • Bulletin of the Korean Chemical Society
    • /
    • 제34권6호
    • /
    • pp.1829-1834
    • /
    • 2013
  • The nucleophilic substitution reactions of Y-aryl ethyl isothiocyanophosphates with substituted X-anilines and deuterated X-anilines were investigated kinetically in acetonitrile at $75.0^{\circ}C$. The free energy relationships with X in the nucleophiles exhibited biphasic concave downwards with a break point at X = H. A stepwise mechanism with rate-limiting bond formation for strongly basic anilines and with rate-limiting bond breaking for weakly basic anilines is proposed based on the negative and positive ${\rho}_{XY}$ values, respectively. The deuterium kinetic isotope effects (DKIEs; $k_H/k_D$) changed gradually from primary normal with strongly basic anilines, via primary normal and secondary inverse with aniline, to secondary inverse with weakly basic anilines. The primary normal and secondary inverse DKIEs were rationalized by frontside attack involving hydrogen bonded, four-center-type TSf and backside attack involving in-line-type TSb, respectively.

리튬 이온 이차전지 Cathode용 Li(Mn$_{1-}$$\delta$Nb$\delta$)$_2$O$_4$의 전기적 특성 (Electrical Characteristics of Li(Mn$_{1-}$$\delta$Nb$\delta$)$_2$O$_4$ Cathode Materials for Li-Ion Secondary Batteries)

  • 오용주;유광수
    • 한국세라믹학회지
    • /
    • 제35권9호
    • /
    • pp.995-1001
    • /
    • 1998
  • As a basic study for cathode materials of {{{{ { {LiMn }_{2 }O }_{4 } }}-based lithium-ion secondary batteries Li({{{{ { { { {Mn }_{1-$\delta$ }Nb }_{$\delta$} )}_{2 }O }_{4 } }} ($\delta$=0.05, 0.1, 0.2) materials which Nb is substituted for Mn were synthesized by the solid state reaction at 80$0^{\circ}C$ and 110$0^{\circ}C$ respectively. The second phase {{{{ { LiNbO}_{3 } }} appeared above $\delta$=0.1 As the result of im-pedance analysis as the amount of substituted Nb increased the resistivity of grain boundary increased greatly. Compared to undoped-{{{{ { {LiMn }_{2 }O }_{4 } }} the electrical conductivity of Li({{{{ { { { {Mn }_{1-$\delta$ }Nb }_{$\delta$} )}_{2 }O }_{4 } }} decreased slightly but is charging capacity and potential plateau increased.

  • PDF

Nickel-Catalyzed Hydrogenolysis of Arenesulfonates Using Secondary Alkyl Grignard Reagents

  • Kim, Chul-Bae;Cho, Chul-Hee;Park, Kwang-Yong
    • Bulletin of the Korean Chemical Society
    • /
    • 제28권2호
    • /
    • pp.281-284
    • /
    • 2007
  • Neopentyl arenesulfonates react with secondary alkylmagnesium chlorides in the presence of dppfNiCl2 to produce the corresponding arenes via the reductive cleavage of carbon-sulfur bond. Highest yield is obtained by using three equivalents of Grignard reagent to a mixture of arenesulfonate and dppfNiCl2 in Et2O at room temperature. This reaction represents a novel method allowing the efficient hydrogenolysis of sulfur-containing groups in aromatic compounds.

MOVPE of ZnSe with DIPSe and DMZn

  • Soo, Huh-Jeung;Ok, Lim-Jeong
    • Journal of Korean Vacuum Science & Technology
    • /
    • 제2권2호
    • /
    • pp.118-121
    • /
    • 1998
  • Diisopropylselenide (DIPSe) is employed for the metalorganic vapor phase epitaxy (MOVPE) of ZnSe in order to eliminate premature gas phase reaction while maintaining negligible carbon incorporation and preserving relatively low growth temperature. In combination with dimethylzinc, single crystalline ZnSe layers were grown on GaAs at temperature around 450$^{\circ}C$. Secondary ion mass spectrometry showed a negligible carbon incorporation in ZnSe films grown from DIPSe even at high [Ⅵ]/[II] ratios, in contrast of a carbon concentration of 1021 cm-3 in ZnSe films grown from diallyselenide (DASe). Crystalline and interface quality are demonstrated by secondary electron microscopy, secondary ion mass spectroscopy and double crystal X-ray diffraction.

  • PDF

An Experimental Study on the Combustion Characteristics of a Low NOx Burner Using Reburning Technology

  • Ahn, Koon-Young;Kim, Han-Seok;Son, Min-Gyu;Kim, Ho-Keun;Kim, Yong-Mo
    • Journal of Mechanical Science and Technology
    • /
    • 제16권7호
    • /
    • pp.950-958
    • /
    • 2002
  • The combustion characteristics of a low NOx burner using reburning technology have been experimentally studied. The return burner usually has three distinct reaction zones which include the primary combustion zone, the reburn zone and the burnout zone by provided secondary air. NOx is mainly produced in a primary combustion zone and a certain portion of NOx can be converted to nitrogen in the rebury zone. In the burnout zone, the unburned mixtures are completely oxidated by supplying secondary air. Liquefied Petroleum Gas (LPG) was used as main and reburn fuels. The experimental parameters investigated involve the main/reburn fuel ratio, the primary/secondary air ratio, and the injection location of rebury fuel and secondary air. When the amount of return fuel reaches to the 20-30% of the total fuel used, the overall NO reduction of 50% is achieved. The secondary air is injected by two different ways including vertical and parallel injection. The injector of secondary air is located at the downstream region of furnace for a vertical-injection mode, which is also placed at the inlet primary-air injection region for a parallel-injection mode. In case of the vertical injection of the secondary air flow, the NOx formation of stoichiometric condition at a primary combustion zone is nearly independent of the rebury conditions (locations, fuel/air ratios) while the NOx emission of the fuel-lean condition is considerably influenced by the reburn conditions. In case of the parallel injection of the secondary air, the NOx emission is sensitive to the air ratio rather than the fuel ratio and the reburning process often coupled with the multiple air-staging and fuel-staging combustion processes.

아민고정화 MCM-41 염기촉매를 이용한 Knoevenagel 축합반응 (Knoevenagel Condensation Reaction Using Amine-functionalized MCM-41 Base Catalysts)

  • 최정식;안화승
    • Korean Chemical Engineering Research
    • /
    • 제44권4호
    • /
    • pp.417-423
    • /
    • 2006
  • 실리카계 메조 물질 MCM-41 지지체 위에 여러 방법으로 aminopropyltrimethoxysilane(APMS)을 표면 기능화 시킨 염기촉매를 제조하였고 표준 염기반응인 Knoevenagel 축합반응을 수행하여 촉매적 활성을 측정하였다. Methyltrimethoxysilane으로 추가 표면처리하거나, APMS를 염소함유 유기실란과 축합하여 2차 아민 형성 후 고정화시킨 MCM-41 촉매(BAPM)를 제조한 결과, MCM-41 표면의 잔류 OH를 제거하고 물과의 수소결합으로 아민 활성점의 기능이 약화되는 것을 억제하여 높은 TON을 얻을 수 있었다. 코팅에 의해 표면에 많은 양의 아민이 고정화된 MCM-41은, 세공 내부의 반응 공간이 줄어들고, 인접한 아민 간의 수소결합으로 인하여 낮은 염기도가 예상되며 촉매 활성도 상대적으로 낮았다. 제조한 촉매 중에는 BAPM이 촉매 활성이 가장 우수하였다.

이드반응이 동반된 족부백선 환자 치험 1례 (The Case Report of Tinea Pedis with Id Reaction)

  • 권강;김철윤;이동진;김남권;서형식
    • 한방안이비인후피부과학회지
    • /
    • 제28권1호
    • /
    • pp.134-142
    • /
    • 2015
  • Objective : This study was carried out to find out the effect of Korean medical treatments on tinea pedis with id reaction. Method : We treated a 33-year-old man was afflicted with tinea pedis complicating id reaction with herbal medicine, acupuncture, ointment, wet-dressing and steam treatment. After treatments, we measured the status of scales, fissures and the degree of pruritus. We followed up symptom changes by taking pictures and compared before and after. Result & Conclusion : Three days after admission, erythema occurred at upper and lower limbs and the degree of pruritus increased by id reaction. As tinea pedis improved, id reaction decreased, too. Consequently, both sites of primary lesions of tinea pedis and secondary id reactions were significantly improved, and accompanied symptoms were resolved simultaneously.