• Title/Summary/Keyword: Y-4

Search Result 364,407, Processing Time 0.178 seconds

Synthesis of 4-(2, 4 dioxo-5-pyrimidyl)-1, 4-dihydropyridine Derivatives

  • Suh, Jung-Jin;Hong, You-Hwa;Bae, Myn
    • Archives of Pharmacal Research
    • /
    • v.13 no.4
    • /
    • pp.310-313
    • /
    • 1990
  • Hantzsch synthesis of 5-formyluracil (1) methyl acetoacetate (2) and methyl 3-aminocrotonate (3) gave 2, 6-dimethyl-4-(2, 4-dioxo-5-pyrimidy)-1, 4-dihydropyridine-3, 5-dicarboxylic acid dimethylester (4a) in 54.6 yield. As the same procedure, 1, 3-dimethyl-5-formyl-uracil (6) gave 2, 6-dimethyl-4-(1, 3-dimethyl-2, 4-dioxo-5-pyrimidyl)-1, 4-dihydropyridine-3, 5-dicarboxylic acid dimethyl easter (7a) IN 52.2% yield. 4a was methylated to afford 7a also in 52% yield.

  • PDF

Synthesis of 4-Hydroxycoumarion Derivatives-1: An Efficient Synthesis of Flocoumafen

  • Park, Oee-Sook;Jang, Bong-Suek
    • Archives of Pharmacal Research
    • /
    • v.18 no.4
    • /
    • pp.277-281
    • /
    • 1995
  • An anticoagulant, 4-hydroxy-3-[1, 2, 3, 4-tetrahydro-3-[4-(4-trifluoromethylbenzyloxy)phenyll-1 -naphthyl]coumarin (Flocoumafen) was synthesized in 8 steps starting from phenylacetyl shloride and anisole. The key step in the synthesis involves the reaction of 3-(4-methoxyphenyl)-1-teralol with 4-hydroxycoumarin to give 4-hydroxy-3 [1, 2, 3, 4-tetrahydro-3-[4-emthoxyphenyl]-1-naphthyl]coumarin.

  • PDF

Effect of Microstructures and Sintering Additives on the Mechanical Properties of Si$_3$N$_4$ (질화규소의 기계적 특성에 미치는 미세구조 및 소결조제의 영향)

  • Park, Hye-Ryeon;Lee, O-Sang;Park, Hui-Dong;Lee, Jae-Do
    • Korean Journal of Materials Research
    • /
    • v.2 no.5
    • /
    • pp.330-336
    • /
    • 1992
  • Four distinctive hot pressed and heat treated S${i_3}{N_4}$ceramics, S${i_3}{N_4}$-8%${Y_2}{O_3}$, S${i_3}{N_4}$-6% ${Y_2}{O_3}$-2% $A{l_2}{O_3}$, S${i_3}{N_4}$-4% ${Y_2}{O_3}$-3% $A{l_2}{O_3}$, 그리고 S${i_3}{N_4}$-1% MgO-1% Si$O_2$(in wt%), were prepared and characterized by X-ray diffraction, scanning electron microscopy, image analysis and mechanical tests. The fracture toughness of S${i_3}{N_4}$-8% ${Y_2}{O_3}$specimens containing large elongated grains showed the highest value of about 9.8MPa$m^{1/2}$. Two out of four S${i_3}{N_4}$, ceramics(S${i_3}{N_4}$-6% ${Y_2}{O_3}$-2% $A{l_2}{O_3}$and S${i_3}{N_4}$-4% ${Y_2}{O_3}$-3% $A{l_2}{O_3}$) heat treated at 200 $0^{\circ}C$retained the fracture strength of over 900MPa and fracture toughness of over 8.0MPa$m^{1/2}$. Large ${\beta}$-S${i_3}{N_4}$grains having a diameter larger than 1${\mu}$m appeared to contribute to increase in fracture toughness.

  • PDF

PHOTOCHEMICAL REACTIONS OF AROMATIC $\alpha$-DIKETONES

  • Kim, Sung Sik
    • Journal of Photoscience
    • /
    • v.1 no.2
    • /
    • pp.123-126
    • /
    • 1994
  • Irradiation of aromatic $\alpha$-diketones, such as benzil, 4,4'-dimethylbenzil, 4-chlorobenzil, 4,4'-diisopropylbenzil, 3,3,'-dimethylbenzil, in methanol gives rise to xanthone derivatives, in addition to $\alpha$-hydroxyketones. Irradiation of 4,4'-dibromobenzil, 2,2'-pyridil, 2,2'-naphthil and 9,9'-anthril yields only $\alpha$-hydroxyketones, whereas 4,4'-dimethoxybenzil yields methyl 4-methoxybenzoate.

  • PDF

MPEG-4 Contents Authoring using AVI (AVI 데이터를 이용한 MPEG-4 컨텐츠 저작)

  • 이숙영;차경애;김상욱
    • Proceedings of the Korea Multimedia Society Conference
    • /
    • 2002.05d
    • /
    • pp.618-621
    • /
    • 2002
  • MPEG-4 컨텐츠는 비디오, 오디오 파일을 비롯하여 다양한 타입의 미디어로 구성되는 복합 멀티미디어 데이터이다. 본 논문에서는 MPEG-4 컨텐츠 생산을 위해서 저작 환경을 제공하고 이를 MPEG-4 파일로 생성하는 MPEG-4 컨텐츠 저작 도구를 제안한다. 특히 제안하는 MPEG-4 저작 도구는 AVI 형태의 동영상 자료를 입력 받아, MPEG-4 오디오, 비디오 데이터로 변환하고 이를 MPEG-4 장면 저작에 이용할 수 있다. MPEG-4 컨텐츠는 MPEG-4 파일로 구성되며, 장면 구성이 배제된 오디오, 비디오로만 구성된 MPEG-4 파일과 전체 미디어 데이터가 하나의 장면으로 생성된 MPEG-4 파일이 될 수 있다.

  • PDF

Design of Unified HEVC/VP9 4×4 Transform Block (HEVC/VP9 4×4 Transform 통합 블록 설계)

  • Jung, Seulkee;Lee, Seongsoo
    • Journal of IKEEE
    • /
    • v.19 no.3
    • /
    • pp.392-399
    • /
    • 2015
  • This paper proposes a unified $4{\times}4$ transform architecture for HEVC and VP9 codec to reduce hardware size. It performs HEVC $4{\times}4$ IDCT, HEVC $4{\times}4$ IDST, VP9 $4{\times}4$ IDCT, and VP9 $4{\times}4$ IADST in a unified hardware. HEVC $4{\times}4$ IDCT and VP9 $4{\times}4$ IDCT have same IDCT computation except for the scales of coefficients. Similarly, HEVC $4{\times}4$ IDST and VP9 $4{\times}4$ IADST have same IDST computation except for the scales of coefficients. Furthermore, IDCT and IDST have quite a lot of similarity, so they can share some hardwares in common. So the proposed hardware performs all 4 operations in a unified hardware, where each operation has its own multiplication coefficients with shared butterfly adders. The synthesized block in 0.18 um technology is 6,679 gates, and the gate count is reduced by 25.3% in comparison with conventional designs.

Ulam Stability Generalizations of 4th- Order Ternary Derivations Associated to a Jmrassias Quartic Functional Equation on Fréchet Algebras

  • Ebadian, Ali
    • Kyungpook Mathematical Journal
    • /
    • v.53 no.2
    • /
    • pp.233-245
    • /
    • 2013
  • Let $\mathcal{A}$ be a Banach ternary algebra over a scalar field R or C and $\mathcal{X}$ be a ternary Banach $\mathcal{A}$-module. A quartic mapping $D\;:\;(\mathcal{A},[\;]_{\mathcal{A}}){\rightarrow}(\mathcal{X},[\;]_{\mathcal{X}})$ is called a $4^{th}$- order ternary derivation if $D([x,y,z])=[D(x),y^4,z^4]+[x^4,D(y),z^4]+[x^4,y^4,D(z)]$ for all $x,y,z{\in}\mathcal{A}$. In this paper, we prove Ulam stability generalizations of $4^{th}$- order ternary derivations associated to the following JMRassias quartic functional equation on fr$\acute{e}$che algebras: $$f(kx+y)+f(kx-y)=k^2[f(x+y)+f(x-y)]+2k^2(k^2-1)f(x)-2(k^2-1)f(y)$$.

Synthesis of Certain Substituted Quinoxalines as Antimicrobial Agents (Part II)

  • Mohga.M.Badran;Khaled.A.M.Abouzid;M. H. M. Hussein
    • Archives of Pharmacal Research
    • /
    • v.26 no.2
    • /
    • pp.107-113
    • /
    • 2003
  • Several fused triazolo and ditriazoloquinoxaline derivatives such as 1-aryl-4-chloro-[1,2,4]triazolo[4,3-a]quinoxalines (3a-d), 4-alkoxy[1,2,4]triazolo[4,3-a]quinoxalines (4a,b), 4-substituted-amino-[1,2,4] triazolo[4,3-a]quinoxalines (5a-h), 1-(aryl)-[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-thione (6), 4-(arylidenehydrazino )-1-phenyl-[1,2,4]triazolo[4,3-a]quinoxalines (10a-e) and [1,2,4]ditriazolo[4,3-a:3',4'-c]quinoxaline derivatives (11-13) have been synthesized and some of these derivatives were evaluated for antimicrobial and antifungal activity in vitro. It was found that compounds 3a and 9b possess potent antibacterial activity compared to the standard tetracycline.