• Title/Summary/Keyword: N-N compound

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The Effect of N-Substituted Alkyl Groups on the Anticonvulsant Activities of N-Cbz-${\alpha}$-amino-N-alkylsuccinimides

  • Lee, Jae-Won;Son, Ki-Chun;Jung, Kyung-Im;Choi, Jong-Won;Park, Min-Soo
    • Archives of Pharmacal Research
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    • v.20 no.1
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    • pp.53-57
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    • 1997
  • For the purpose of defining the effects of the N-substituted alkyl groups on the anticonvulsant activities of N-Cbz-.alpha.-aminosuccinimides, various (R)- and (S)-N-alkyl substituted N-Cbz-.alpha.-aminosuccinimides (1 and 2) were prepared from the corresponding (R)- and (S)-N-Cbz-aspartic acid by using known reaction and were evaluated the anticonvulsant activies in the MES and PTZ tests, including their neurotoxicities. The most active compound in the MES test was (R)N-Cbz-.alpha.-amino-N-methylsuccinimide (1b) $(ED_{50}=52.5 mg/kg, Pl=3.2)$. And in case of the PTZ test, (R)-N-Cbz-.alpha.-amino-N-ethylsuccinimide (1c) was the most active compound $(ED_{50}/=32.5mg/kg, Pl=3.1)$. The order of anticonvulsant activities of these compounds against the MES test, as judged from the ED_50values for the R series (1), was N-methyl > N-isobutyl > non-substituted > N-ethyl, N-allyl > N-benzyl compound; for the S series (2) N-methyl > N-altyl > non-substituted > N-isobutyl > N-ethyl > N-benzyl compound. The anticonvulsant activities in the PTZ tests of these compounds exhibited somewhat different pattern ; for the R series (1) Nethyl > N-methyl > N-isobutyl> non-substituted > N-allyl > N-benzyl compound in order of decreasing activity; for S series (2) N-ethyl > N-allyl, non-substituted > N-isobutyl > N-methyl > N-benzyl compound in order of decreasing activity.

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Effect of Air Additions on the Growth Characteristics of the Compound Layer during Oxynitriding in50%NH3+Air+N2 Atmosphere (50% NH3-Air-N2가스분위기에서 Oxynitriding시 Compound Layer의 성장 특성에 미치는 공기첨가효과)

  • Kim, Y.H.;Lee, Y.S.
    • Journal of the Korean Society for Heat Treatment
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    • v.7 no.3
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    • pp.206-218
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    • 1994
  • In 50%$NH_3+Air+N_2$ atmospheres, the effect of air additions on the growth characteristics of the compound layer during oxynitriding at $570^{\circ}C$ for 2hr in carbon and alloy steels has been investigated. The ammount of apparent residual ammonia during oxynitriding has shown to be increased with air additions(9~36 Vol. %) and X-ray diffraction analysis of case oxynitreded has shown that the compound layer consist of ${\varepsilon}-Fe_{2-3}$(N, C) phase and ${\gamma}^{\prime}-Fe_4$(N,C) phase. In the case of carbon steels, the thickness of oxide layer, compound layer and porous layer and the amount of ${\varepsilon}-Fe_{2-3}$(N,C) phase in the compound layer were increased with additions of air in 50%$NH_3+N_2$ atmospheres. At the same gas composition, the thickenss of oxide layer, compound layer and porous layer in alloy steels showed slightly thin layer thickness compared to those of carbon steels and the ${\gamma}^{\prime}-Fe_4$(N,C) phase in the compound layer of alloy steels was found barely. Therefore, the most obvious effect of air addition in the gas nitriding atmosphere has been found to in crease further kinetics of nitriding reaction.

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The Effect of N-Substituted Alkyl Groups on Anticonvulsant Activities of N-Cbz-$\alpha$-amino-N-alkylglutarimides

  • Lee, Jae-Won;Son, Ki-Chun;Jung, Gyung-Im;Kim, Min-Jeong;Choi, Jong-Won;Lee, Eung-Seok;Park, Min-Soo
    • Archives of Pharmacal Research
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    • v.22 no.5
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    • pp.491-495
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    • 1999
  • In order to examine the effects of N-substituted alkyl group on the anticonvulsant activities of N-Cbz-$\alpha$-aminoglutarimides as novel anticonvulsants with broad spectrum, a series of (R) or (S) N-Cbz-$\alpha$-amino-N-alkylglutarimides (1 and 2) were prepared from the corresponding (R) or (S) N-Cbz-glutamic acid and evaluated for the anticonvulsant activities in the maximal electroshock seizure (MES) test and pentylenetetrazol induced seizure(PTZ) test, including the neurotoxicity. The most potent compound in the MES test was (S) N-Cbz-$\alpha$-amino-N-methylglutarimide($ED_{50}$=36.3 mg/kg, PI=1.7). This compound was also most potent in the PTZ test ($ED_{50}$=12.5 mg/kg, PI=5.0). The order of anticonvulsant activities against the MES test as evaluated form $ED_{50}$ values for (R) series was N-methyl > N-H > N-ethyl > N-allyl ; for the (S) series N-methyl > N-H > N-ethyl > N-alkyl > N-isobutyl compound. Against the PTZ tests, the order of anticonvulsant activities showed similar pattern ; for the (R) series, N-methyl > N-H > N-ethyl > N-allyl ; for the (S) series N-methyl > N-H > N-ethyl > N-allyl > N-isobutyl compound. From the above results, N-substituted alkyl groups were though to play an important role for the anticonvulsant activities of N-Cbz-$\alpha$-amino-N-alkylgutarimides.

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Crystal Structure Analysis of N,N'-bis(3-chloro-2-methylsalicylidene)-1,4-butanediamine

  • Sharmila, P.;Rajesh, R.;Venkatesan, R.;Ganapathy, Jagadeesan;Aravindhan, S.
    • Journal of the Chosun Natural Science
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    • v.9 no.4
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    • pp.255-260
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    • 2016
  • The crystal structure of the saliciline derivatives N,N'-bis(3-chloro-2-methylsalicylidene)-1,4-butanediamine ($C_{20}H_{22}Cl_2N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the triclinic space group $P{\bar{i}}$ with unit cell dimension $a=4.6085(3){\AA}$, $b=5.9747(3){\AA}$ and $c=5.9747(3){\AA}$ [${\alpha}=83.889(4)^{\circ}$, ${\beta}=86.744(5)^{\circ}$ and ${\gamma}=82.085(5)^{\circ}$]. The title compound is essentially planar conformation. The compound lies across a crystallographic inversion centre and adopts E configurations with respect to the C-N bonds. The crystal packing of the molecules of compound is stabilized through weak O-H...N intra molecular interactions

Selective Esterification of N-Benzyl-L-aspartic Acid. (I). Some Modified Methods for the Preparation of N-Benzylaspartic Anhydride Hydrobromide

  • Lee Chal-Ho;Chai, Kyu-Yun;Lee, Man-Koo;Chung, Bong-Young
    • Bulletin of the Korean Chemical Society
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    • v.8 no.6
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    • pp.457-459
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    • 1987
  • Racemic N-benzylaspartic acid (4) was prepared from maleic anhydride and used to modify and develop some efficient methods for the preparation of N-benzylaspartic anhydride hydrobromide (5). Thus, successive treatment of the compound 4 with 30% HBr in acetic acid and acetic anhydride afforded the title compound 5 in 75% yield. From this compound 5, ${\alpha}$-benzyl and ${\alpha}$-methyl N-benzylaspartates were also prepared.

Effect of $CO_2$ Content on the Growth and Corrosion Characteristics of the Compound Layers in Gaseous Nitrocarburized Carbon Steels (가스 질화침탄처리한 탄소강의 화합물층 성장 및 부식특성에 미치는 $CO_2$함량의 영향)

  • Kim, Y.H.;Kim, S.D.;Yoon, H.J.
    • Journal of the Korean Society for Heat Treatment
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    • v.15 no.5
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    • pp.219-227
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    • 2002
  • This study has been performed to investigate the effect of $CO_2$ content on the growth characteristics of the compound layer, porous layer and corrosion characteristics of carbon steels after gaseous nitrocarburizing in $70%-NH_3-CO_2-N_2$ at $580^{\circ}C$ for 2.5 hrs. The results obtained from the experiment were the thickness of the compound and porous layers increased with increasing $CO_2$ contents. At the same fixed gas composition the thickness of the compound and porous layer increased with increasing carbon content of the specimens. X-ray diffraction analysis showed that compound layer was mainly consisted of ${\varepsilon}-Fe_{2-3}(N,C)$ and ${\gamma}^{\prime}-Fe_4N$ as the increased with $CO_2$ contents in atmosphere, compound layer was chiefly consisted of ${\varepsilon}-Fe_{2-3}(N,C)$ phase. With increasing $CO_2$ content and total flow rate in gaseous nitrocarburizing, the amount of ${\varepsilon}-Fe_{2-3}(N,C)$ phase in the compound layer was increased. The current density of passivity decreased with increasing $CO_2$ content due to the development of porous layer at the out most surface of ${\varepsilon}-Fe_{2-3}(N,C)$.

The Synthesis of Carbamoylsulfenyl Chloride and its Derivatives (염화카바모일술페닐과 그 유도체의 합성)

  • Surk Sik Moon;Dong Young Oh
    • Journal of the Korean Chemical Society
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    • v.27 no.2
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    • pp.157-164
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    • 1983
  • N-Methylidene-2,6-diethylaniline (III) was prepared by the reaction of 2,6-diethylaniline (II) with an excess paraformaldehyde. The protons of N=$CH_2$in the compound III exhibited a second order NMR spectrum. The compound III reacted with bifunctional chlorocarbonylsulfenyl chloride(IV) to give N-(chloromethyl)-N-(2,6-diethylphenyl)-carbamoylsulfenyl chloride(V). The reaction of the compound V with various alcohols resulted in the formation of Alkyl N-(chloromethyl)-N-(2,6-diethylphenyl)-carbamoylsulfenate esters(VI${\sim}$XVI) in 71${\sim}$95% yields. The compound VI${\sim}$XVI decomposed gradually, but the thermal rearrangement of S-O bonding to S=O bonding was not found. The nucleophilic attack of an excess alcohol to the compound Ⅴ was made on both divalent sulfur and ${\alpha}$-carbon of N-chloromethyl group. The corresponding substituted products(XVII, XVIII) had considerable stability.

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Study on Gaseous Nitrocarburizing Treatment (가스침질탄화법(浸窒炭化法)에 관한 연구(硏究))

  • Lee, S.Y.;Bell, T.
    • Journal of the Korean Society for Heat Treatment
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    • v.1 no.1
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    • pp.8-12
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    • 1988
  • This study has been carried out to evaluate gaseous nitrocarburizing treatment undertaken for pure iron at $570^{\circ}C$ in an atmosphere containing 50% endothermic gas, generated from natural gas, and 50% ammonia. The results obtained from the experiment are as follows ; 1) The microstructure of gaseous nitrocarburized pure iron consists of the compound layer on the surface and the diffusion zone beneath it. The compound layer progresses uniformly into ferrite with a thickness of $20{\mu}$ obtained after treating for 3 hours. 2) Chemical analysis has shown that the compound layer has a C/N ratio of 0.19 and that the average combined interstitial content of the compound layer is about 30 atomic percent, which is close to the lower limit of the ${\varepsilon}$-carbonitride phase field in Fe-C-N phase diagram. 3) X-ray diffraction analysis has revealed that the compound layer consists mainly of the c.p.h. phase, ${\varepsilon}-Fe_3$(C.N) and a small amount of $Fe_4N$ and traces of ferrite are also present in the compound layer. 4) The microhardness of the compound layer is about 600 V.H.N and shows a relatively sharp fall-off at the compound layer/diffusion zome interface. 5) The average actual degree of ammonia dissociation is calculated to be 27% for a gaseous nitrocarburizing treatment carried out at $570^{\circ}C$.

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High-Voltage GaN Schottky Barrier Diode on Si Substrate Using Thermal Oxidation (열 산화공정을 이용하여 제작된 고전압 GaN 쇼트키 장벽 다이오드)

  • Ha, Min-Woo;Roh, Cheong-Hyun;Choi, Hong-Goo;Song, Hong-Joo;Lee, Jun-Ho;Kim, Young-Shil;Han, Min-Koo;Hahn, Cheol-Koo
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1418-1419
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    • 2011
  • 차세대 전력 반도체인 고전압 GaN 쇼트키 장벽 다이오드의 역방향 특성을 개선하기 위해서 열 산화공정이 제안되었다. AlGaN/GaN 에피탁시 위에 쇼트키 장벽 다이오드 구조가 제작되었으며, 쇼트키 컨택은 증착 후 $450^{\circ}C$에서 산화되었다. 열 산화공정이 메사 측벽의 AlGaN 및 GaN 표면에 $AlO_x$$GaO_x$를 형성하여 표면으로 흐르는 누설전류를 억제한다. 표면 및 GaN 버퍼를 통한 누설전류는 열 산화 공정 이후 100 ${\mu}m$-너비당 51.3 nA에서 24.9 pA로 1/2000 배 수준으로 감소하였다. 표면 산화물 형성으로 인하여 생성된 Ga-vacancy와 Al-vacancy는 acceptor로 동작하여 surface band bending을 증가시켜 쇼트키 장벽 높이를 증가시킨다. 애노드-캐소드 간격이 5 ${\mu}m$인 제작된 소자는 0.99 eV의 높은 쇼트키 장벽 높이를 획득하여, -100 V에서 0.002 A/$cm^2$의 낮은 누설전류를 확보하였다. 애노드-캐소드 간격이 5에서 10, 20, 50 ${\mu}m$로 증가되면 소자의 항복전압은 348 V에서 396, 606, 941 V로 증가되었다. 열 산화공정은 전력용 GaN 전자소자의 누설전류감소와 항복전압 증가를 위한 후처리 공정으로 적합하다.

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Structural Control of the Compound Layers formed during Nitrocarburising in NH3-Air-C3H8 Atmospheres (NH3-Air-C3H8 분위기에서 Nitrocarburisng시 형성된 Compound Layer의 조직제어)

  • Kim, Y.H.;Choi, K.W.
    • Journal of the Korean Society for Heat Treatment
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    • v.8 no.4
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    • pp.289-301
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    • 1995
  • The effect of Air/$C_3H_8$ gas addition on the compound layer growth of steels nitrocarburised in $NH_3+Air+C_3H_8$ mixed gas atmospheres was investigated. It is considered that amount of residual $NH_3$ was varied according to alternation of Air/$C_3H_8$ mixing ratio and volume content. The compound layer formed from nitrocarburising was composed of ${\varepsilon}-Fe_{2-3}$(C, N) and ${\gamma}^{\prime}-Fe_4$(C, N). According as Air/$C_3H_8$ mixing ratio increased, the superficial content of ${\gamma}^{\prime}-Fe_4$(C, N) within the compound layer was increased, at the same time the growth rate of compound layer and porous layer was increased. In the case of alloy steel at the fixed gas composition, the growth rate of compound layer and porous layer was worse than carbon steel and compound layer phase composition structure primarily consisted of E phase. As the carbon content of materials was increasing in the given gas atmospheres, the growth rate of compound layer and porous layer was increased and the superficial content of ${\varepsilon}-Fe_{2-3}$(C, N) within the compound layer was increased.

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