• Title/Summary/Keyword: Amides

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$^{13}C$nmr Studies on the Interaction of Lithium Salts to Formamide, Acetamide and Propionamide Systems (Formamide, Acetamide 및 Propionamide계에 대한 리튬염의 상호작용에 관한 $^{13}C$ nmr 연구)

  • Dae-Ho Shin;Jo W. Lee;Young Sang Choi
    • Journal of the Korean Chemical Society
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    • v.26 no.5
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    • pp.291-295
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    • 1982
  • $^{13}C$resonances of carbonyl and various alkyl groups in amides are found to shift down-field on the interaction with lithium salts and it is shown that lithium ion binds directly to the carbonyl group in amides. The magnitudes of the $^{13}C$ chemical shifts of various amides depend not only on the size of alkyl groups in amides but also on the interaction with anion. The change of $^{13}C$chemical shift of amide in LiCl is smaller than that in$LiClO_4$ due to the difference of the charge density of the anion.

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Liquid Chromatographic Resolution of Racemic $\alpha$-Amino Acid Derivatives on an Improved $\pi$-Acidic Chiral Stationary Phase Derived from (S)-Leucine

  • 현명호;이승준;류재정
    • Bulletin of the Korean Chemical Society
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    • v.19 no.10
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    • pp.1105-1109
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    • 1998
  • A chiral stationary phase derived from (S)-N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkyl amide (CSP 2) was applied in separating the two enantiomers of various π-basic aromatic derivatives of leucine N-propyl amide in order to evaluate π-basic aromatic groups as an effective derivatizing group for the resolution of a-amino acids. Subsequently N-(3,5-dimethoxybenzoyl) group was found to be very effective as a π-basic aromatic derivatizing group. Based on these results, N-(3,5-dimethoxybenzoyl) derivatives of various a-amino N-propyl amides, N,N-diethyl amides and esters were resolved on the CSP derived from (S)-N-(3,5-dinitrobenzoyl) leucine N-phenyl N-alkyl amide (CSP 2) and the resolution results were compared with those on the CSP derived from (S)-N-(3,5-dinitrobenzoyl)leucine N-alkyl amide (CSP 1). The enantioselectivities exerted by CSP 2 were much greater than those exerted by CSP 1. In addition, racemic N-(3,5-dimethoxybenzoyl)-a-mino N,Ndiethyl amides were resolved much better than the corresponding N-(3,5-dimethoxybenzoyl)-a-mino N-propyl amides and esters on both CSPs. Based on these results, a chiral recognition mechanism utilizing the π-π donor-acceptor interaction and the two hydrogen bondings between the CSP and the analyte was proposed.

Synthesis and Catalytic Activity of Water-Soluble Iridium-Sulfonated Triphenylphosphine Com;lex. Hydration of Nitriles

  • 진종식;김상열;주광석;원경식;종대성
    • Bulletin of the Korean Chemical Society
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    • v.20 no.5
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    • pp.535-538
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    • 1999
  • Five coordinated water-soluble iridium(l) complex, IrH(CO)(TPPTS)3 (1) (TPPTS = P(m-C6H4SO3Na)3-xH2O) has been prepared from the reaction of IrCl3·3H2O with TPPTS and HCHO in H2O/EtOH solution. Complex 1 catalyzes the hydration of nitrites (RC ≡ N, R = CH3, CICH2, CH3(CH2)4, Ph) in aqueous solution to give the corresponding amides (RCONH2) at 100℃. The hydration of unsaturated nitrites (R'C ≡ N, R'=CH3CH=CH, CH3OCH=CH, trans-PhCH=CH, CH2=C(CH3)) takes place regioselectively on-C ≡ N group to give unsaturated amides (R'CONH2) leaving the olefinic group intact. The yields of the amides seem to be depending on the electrophilicity of the carbon of nitrile: The more the electron withdrawing ability of the substituents on nitrites, the more amides are obtained. The hydration of dinitriles (NC-R-CN, R=(CH2)4, (CH2)6) with complex 1 initially gives mono-hydration products (NC-R-CONH2) which are slowly hydrated further to give dihydration products (H2NCO-R-CONH2). The hydration of 1,4-dicyanobutane has been found to be somewhat faster than that of 1,6-dicyanohexane.

Application of Cl3CCONH2/PPh3 towards the Synthesis of Bioactive Amides

  • Chaysripongkul, Skydow;Pluempanupat, Wanchai;Jang, Doo-Ok;Chavasiri, Warinthorn
    • Bulletin of the Korean Chemical Society
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    • v.30 no.9
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    • pp.2066-2070
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    • 2009
  • $Cl_3CCONH_2$ coupled with $PPh_3$ was determined to be an effective reagent for the conversion of carboxylic acids to their corresponding acid chlorides. Subsequently, these acid chlorides were successfully trapped with amines in the presence of 4-picoline, yielding amides. This practical and efficient protocol can be utilized for the synthesis of biological amides in excellent yields.

New Aromatic Amides from Aconitum pseudo-laeve var. erectum (진범 전초의 새로운 aromatic amides 성분)

  • Kim, Dae-Geun;Gwak, Jong-Hwan;Gwon, Hak-Cheol;Song, Gi-Won;Ji, Ok-Pyo;Lee, Gang-No
    • YAKHAK HOEJI
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    • v.40 no.4
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    • pp.418-421
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    • 1996
  • From the ethanol extract of the whole plant of Aconitum pseudo-laeve var. erectum Nakai, three new aromatic amides, methyl-N-acetyl anthranilate, methyl-N-(3-ethox ycarbonylpropionyl)anthranilate, methyl-N-(3-methoxycarbonylpropionyl) anthranilate were isolated and characterized on the basis of spectral data.

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Synthesis of 7-Hydroxy-4-Oxo-4H-Chromene- and 7-Hydroxychroman-2-Carboxylic Acid N-Alkyl Amides and Their Antioxidant Activities

  • Kwak, Jae-Hwan;Kang, Hae-Eun;Jung, Jae-Kyung;Kim, Hwa-Jung;Cho, Jung-Sook;Lee, Hee-Soon
    • Archives of Pharmacal Research
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    • v.29 no.9
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    • pp.728-734
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    • 2006
  • A series of 7-hydroxy-4-oxo-4H-chromene- (3a - h) and 7-hydroxychroman-2-carboxylic acid N-alkyl amides (4a - g) were synthesized and their antioxidant activities were evaluated. While compounds 3a - h were less active, compounds 4a - g exhibited more potent inhibition of lipid peroxidation initiated by $Fe^{2+}$ and ascorbic acid in rat brain homogenates. Among them, 7-hydroxychroman-2-carboxylic acid N-alkylamides (4e - g) bearing nonyl, decyl, and undecyl side chain exhibited 3 times more potent inhibition than trolox (1).

Effects of Li$^+$ and Ag$^+$ Ions on the Rotational Barrier in Acetamide and propionamide System

  • Kwon, Dae-Keun;Choi, Young-Sang;Yoon, Chang-Ju
    • Bulletin of the Korean Chemical Society
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    • v.7 no.1
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    • pp.1-5
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    • 1986
  • The influences of $LiNO_3\;and\;AgNO_3$ on the N-C(O) rotational barrier of N,N-dimethylacetamide and N,N-dimethylpropionamide have been investigated. The rotational activation free energy $({\Delta}G^{\neq})\;for\;Li^{+}$-amide complexes is found to increase with increasing salt concentration. On the other hand, that for $Ag^+$-amide complexes increases in the presence of $Ag^+$ ion up to 0.25 M ion concentration and then decreases as the concentration of $Ag^+$ ion is further increased. Such an unusual behavior of $Ag^+$-amide complexes has been interpreted in terms of ion-pairing and diluent effect on the amides. However, $^{13}C$ nmr chemical shift data for the amides have shown that both of these ions interact primarily with the carbonyl group in amides.