• Title/Summary/Keyword: benzylidene

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The Synthesis, NMR Sepectrum and MO Theoretical Studies on MBBA and EBBA (MBBA와 EBBA의 합성 NMR 스펙트럼과 분자궤도함수론적 연구)

  • Kim, Ui Rak;Jeon, Mu Sik;Kim, Un Seop;Chae, Yeong Bok
    • Journal of the Korean Chemical Society
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    • v.18 no.4
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    • pp.239-243
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    • 1974
  • By means of NMR spectrum analysis of the synthesized MBBA and EBBA, it has been found that benzene rings of p-n-butylaniline in both MBBA and EBBA molecules do not conjugate with the central double bond and the benzene ring is twisted from molecular plane of N-(p-methoxy or ethoxy benzylidene) group. And as a result of MO studies, the minimum energy conformation is found for the conformation of $30^{\circ}$ twisted angle. One sees reasonable agreement between theory and experiment.

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Direct Syntheses of $\beta-Mannopyranosyl$ Disaccharides from 4,6-O-Benzylidene Derivatives of Ethylthio $\alpha-D-Mannopyranosides$ Donors

  • Yun, Mi Gyeong;Sin, Yeong Suk;Cheon, Geun Ho
    • Bulletin of the Korean Chemical Society
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    • v.21 no.6
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    • pp.562-566
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    • 2000
  • $\beta-D-Mannopyranosyl$ disaccharides have been obtained from the coupling of 4,6-O-benzylidene derivatives of ethylthio $\alpha-D-mannopyranoside$ employing NIS-TfOH promoter. NIS-TfOH promoted couplings of the corresponding ethylthio $\beta-D-glucopyranoside$ and produced $\alpha-D-glucopyranosyl$ disaccharides. IDCP (iodonium dicollidine perchlorate) was inactive toward the 4,6-O-benzylidenated ethylthio glucopyranosyl donor. However,lDCP coupled the 4,6-O-benzylidenated $ethylthio-\beta-D-galactopyranoside$ to give a-D-galactopyranosyl disaccharides.

Kinetics and Mechanism of the Addition of Benzylamines to Benzylidene Meldrum's Acids in Acetonitrile

  • Oh, Hyuck-Keun;Kim, Tae-Soo;Lee, Hai-Whang;Lee, Ik-Choon
    • Bulletin of the Korean Chemical Society
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    • v.24 no.2
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    • pp.193-196
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    • 2003
  • Nucleophilic addition reactions of benzylamines $(XC_6H_4CH_2NH_2)$ to benzylidene Meldrum's acids (BMA; $YC_6H_4CH=C(COO)_2C(CH_3)_2$) have been investigated in acetonitrile at 20.0 ℃. The rates of addition are greatly enhanced due to the abnormally high acidity of Meldrum's acid. The magnitudes of the Hammett $({\rho}_X\;and\;{\rho}_Y)$ and Bronsted $({\rho}_X$)$ coefficients are rather small suggesting an early transition state. The sign and magnitude of the cross-interaction constant, ${\rho}_{XY}$ (= -0.33), and kinetic isotope effects $(k_H/k_D\;{\stackrel}{~}{=}\;1.5-1.7)$ involving deuterated benzylamine nucleophilies $(XC_6H_4CH_2ND_2)$ are indicative of hydrogen-bonded cyclic transition state. The activation parameters, ${\Delta}H^{\neq}\;{\stackrel}{~}{=}\;4\;kcal\;mol^{-1}\;and\;{\Delta}S^{\neq}\;{\stackrel}{~}{=}\;-37\;e.u.$, are also in line with the proposed mechanism.

Comparison of Some 3-(Substituted-Benzylidene)-1, 3-Dihydro-Indolin Derivatives as Ligands of Tyrosine Kinase Based on Binding Mode Studies and Biological Assay

  • Olgen, Sureyya
    • Archives of Pharmacal Research
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    • v.29 no.11
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    • pp.1006-1017
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    • 2006
  • A series of 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-one, 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-thione and 2, 2'-dithiobis 3-(substituted-benylidene)-1, 3-dihydro-indole derivatives was investigated as inhibitor of $p60^{c-Src}$tyrosine kinase by performing receptor docking studies and inhibitory activity toward tyrosine phosphorylation. Some compounds were shown to be docked at the site, where the selective inhibitor PP1 [1-tert-Butyl-3-p-tolyl-1H-pyrazolo[3,4-d]pyrimidine-4-yl-amine] was embedded at the enzyme active site. Evaluation of all compounds for the interactions with the parameters of lowest binding energy levels, capability of hydrogen bond formations and superimposibility on enzyme active site by docking studies, it can be assumed that 3-(substituted-benzylidene)-1, 3-dihydro-indolin-2-one and thione derivatives have better interaction with enzyme active site then 2, 2'-dithiobis 3-(substituted-benzylidene)-1, 3-dihydro indole derivatives. The test results for the inhibitory activity against tyrosine kinase by Elisa method revealed that 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-thione derivatives have more activity then 3-(substituted-benylidene)-1, 3-dihydro- indolin-2-one derivatives.

Acetate-Promoted Aldol-Type Reaction: Scope and Reactivity of Acetates and Aldehydes

  • Kim, Dong-Hyeon;Rahman, A. F. M. Motiur;Jeong, Byeong-Seon;Lee, Eung-Seok;Jahng, Yurng-dong
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.797-802
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    • 2009
  • Potential of acetates and related compounds in glacial acetic acid as a catalyst for aldol-type condensation reactions was examined. Reactions of cycloalkanones or selected heteroaromatics with aldehydes in presence of 10 mol% of various acetates in acetic acid afforded ${\alpha},{\alpha}$'-bis(substituted-benzylidene)cycloalkanones and substituted-benzylidene-mackinazolinones, respectively, in good yields. Among the compounds tested, ammonium acetate is the best and effective especially towards the reactions of mackinazolinone and aliphatic aldehydes to afford 6-alkylidenemackinazolinones.

Ammonium Acetate: An Efficient Reagent for the One-pot Synthesis of 5-Aryl-7,8,13,14-tetrahydrodibenzo[a,i] phenanthridines, 2,4-Diaryl-6,7-benzo-3-azabicyclo[3.3.1]nonan-9-ones and α,α'-Bis(substituted benzylidene)cycloalkanones

  • Karthikeyan, Natesan Sundaramurthy;Sathiyanarayanan, Kulathu Iyer;Aravindan, Paduthapillai Gopal
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2555-2558
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    • 2009
  • The condensation of cyclic ketone with aromatic aldehydes in the presence of ammonium acetate under ethanol media affords the corresponding 5-aryl-7,8,13,14-tetrahydrodibenzo[a,i]phenanthridine with excellent yield. This mild and efficient procedure with high yield is also applied to the synthesis of 2,4-diaryl-6,7-benzo-3-azabicyclo- [3.3.1]nonan-9-ones and ${\alpha},{\alpha}{$’-bis(substituted benzylidene)cycloalkanones.

Syntheses of Mannosidic Disaccharides from Derivatives of Ethylthio $\alpha$-D-Mannopyranoside

  • 윤미경;신영숙;윤신숙;전근호;Shin, Jeong E. Nam
    • Bulletin of the Korean Chemical Society
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    • v.19 no.11
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    • pp.1239-1244
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    • 1998
  • Derivatives of ethylthio α-D-mannopyranoside as glycosyl donors are compared in coupling efficiency and stercoselectivity with varying thiophilic promoters from methyl triflate (MeOTf), dimethyl(methylthio)sulfonium triflate (DMTST) to iodonium dicollidine perchlorate (IDCP), solvents and glycosyl acceptors. IDCP was the most efficient promoter in coupling of perbenzylated ethylthio-α-D-mannopyranosides (1 and 2), giving α-Dmannosyl disaccharides preferentially, whereas inactive in coupling of 4,6-O-benzylidene derivatives 3 and 4. MeOTf and DMTST promoted coupling of 4,6-O-benzylidene derivatives 3 and 4, but P-D-mannopyranosyl disaccharides were formed preferentially. Coupling reaction was retarded as solvent polarity decreased.

HANTZSCH DIHYDROPYRIDINE: AN EFFECTIVE AND CONVENIENT REGIOSELECTIVE REDUCING AGENT FOR 5-BENZYLIDENE-2,4- THIAZOLIDINEDIONE DERIVATIVES

  • Lee, Hong-Woo;Kim, Bok-Young;Ahn, Joong-Bok;Son, Hoe-Joo;Lee, Jae-Wook;Ahn, Soon-Kil;Hong, Chung-Il
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.252.3-252.3
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    • 2003
  • An effective and convenient regioselective reduction of 5-benzylidene 2,4-thiazolidinedione derivatives to the corresponding 5-benzyl 2,4-thiazolidinedione derivatives has been accomplished using 3,5-dicarboethoxy-2,6-dimethyl-1,4-dihydropyridine (Hantzsch dihydropyridine ester: HEH) with silica gel as an acid catalyst in a good yield.

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Several Polygalitol Derivatives (Polygalitol의 신유도체)

  • 김제훈
    • YAKHAK HOEJI
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    • v.6 no.1
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    • pp.17-18
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    • 1962
  • Several polygalitol derivatives, 4,6-benzylindene-polygalitol, 2,3-diacetyl-4,6-benzylidene-polygalitol and 2,4-diacetyl-polygalitol which might be useful to the preparation of partial condensation products of polygalitol, have been described.

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