• Title/Summary/Keyword: Benzaldehydes

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Synthetic Route for New (Z)-5-[4-(2-Chloroquinolin-3-yl) Methoxy]benzylidinethiazolidine-2,4-diones

  • Jawale, Dhanaji V.;Pratap, Umesh R.;Mane, Ramrao A.
    • Bulletin of the Korean Chemical Society
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    • v.32 no.7
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    • pp.2171-2177
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    • 2011
  • Synthetic route has been developed for the synthesis of new (Z)-5-[4-(2-chloroquinolin-3-yl) methoxy]benzyl-idinethiazolidine-2,4-diones (6a-h) starting from 2-chloro-3-hydroxymethyl quinolines (2a-h). The hydroxy methyl quinolines on tosylation yielded (3a-h). Condensation of the tosyl intermediates with 4-hydroxy benzaldehydes has been carried in DMF in presence of $K_2CO_3$ and obtained 4-quinolinyl methoxy benzaldehydes (4a-h). Conveniently Knoevenagel condensation of quinolinyl methoxy benzaldehydes (4a-h) and 2, 4-thiazolidinedione (5) has been carried in PEG-400 in presence of L-proline and obtained better yields of the titled compounds (6a-h).

Facile Synthesis of Aldehyde-focal Fréchet Type Dendrons and Dendrimers via Staudinger/Aza-Wittig Reactions

  • Han, Seung-Choul;Jin, Sung-Ho;Lee, Jae-Wook
    • Bulletin of the Korean Chemical Society
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    • v.32 no.10
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    • pp.3624-3628
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    • 2011
  • Fr$\acute{e}$chet-type dendritic benzaldehydes were efficiently synthesized using 3,5-dihydroxybenzaldehyde as an aldehyde focal point functionalized unit by adding a generation to the existing dendron or direct oxidation of Fr$\acute{e}$chet-type dendritic benzyl alcohols. These dendritic benzaldehydes were applied for the construction of dendrimers containing secondary amines as connectors via Staudinger/aza-Wittig Reactions with ${\alpha}$,${\alpha}'$,-diazidop-xylene core.

Concentration and Solvent Effects upon Carbonyl Streching Frequency Shifts of Raman Spectra: 4-Substituted Benzaldehydes

  • Jeong, Yeong Mi;Gang, Jae Su;Seo, Seung Heon;Lee, Mu Sang
    • Bulletin of the Korean Chemical Society
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    • v.17 no.2
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    • pp.128-131
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    • 1996
  • From Raman spectra, the ${\nu}g$C=O frequencies of 4-substituted benzaldehydes were found to correlate with the ${\sigma}_p$ values of the 4-x atom or group as well as the acceptor number (AN) values of solvents. In various solvents, the ${\nu}g$C=O frequency of benzaldehyde decreased upon the increase of benzaldehyde concentration. This shift was mainly due to the hydrogen bonding between the carbonyl oxygen and/or aldehydic proton of benzaldehyde and the solvent molecules. Over the 1-80 volume % change, the ${\nu}g$C=O frequency of benzaldehyde down shifted from 1709.4 $cm^{-1}$ to 1700.2 $cm^{-1}$ in CCl4 solution and from 1703.0 $cm^{-1}$ to 1698.0 $cm^{-1}$ in $C_2H_5OH$ solution. This is due to the fact that hydrogen bonding between the benzaldehyde and C2H5OH was much stronger than that between the benzaldehyde and the other solvents.

Synthesis and Absorption Spectral Properties of Bis-methine Dyes Exemplified by 2,5-Bis-arylidene-1-dicyanomethylene-cyclopentanes

  • Asiri, Abdullah Mohamed
    • Bulletin of the Korean Chemical Society
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    • v.24 no.4
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    • pp.426-430
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    • 2003
  • A range of methine dyes has been synthesized by condensation of highly electronegative active methylene compound dicyanomethylenecyclopentane derived from cyclopentanone with the formyl group of substituted benzaldehydes. The electronic absorption spectroscopic properties of the dyes were investigated. In general, substituents on the aromatic aldehyde moiety have a significant effect on the visible absorption maxima of the dyes; increasing the solvent polarity also showed a pronounced effect on the absorption maxima.

Oxidative N-Debenzylation of N-Benzyl-N-substituted Benzylamines Catalyzed by Cytochrome P450

  • Kim, Sung-Soo;Lin, Gang;Yang, Ji-Won
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.249-252
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    • 2004
  • Cytochrome P450 (P450)/$O_2$/NADPH engender electron transfer reaction of N-benzyl-N-substituted benzylamines to yield corresponding radical cation 1 that is simultaneously converted into 2 and 3. Subsequently, expulsion of proton and hydroxylation yielding a-hydroxylamines are followed by formation of benzaldehydes and benzylamines.

Michaelis-Menten Behaviour in the Oxidation of Benzaldehydes by Pyridinium Chlorochromate (Corey's Reagent)

  • Ganesh P. Panigrahi;Sasananda Padhy
    • Bulletin of the Korean Chemical Society
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    • v.13 no.5
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    • pp.547-550
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    • 1992
  • The oxidation of benzaldehyde, 3,4-dimethoxy benzaldehyde, p-methoxy benzaldehyde, m-$NO_2$-benzaldehyde, and m-chlorobenzaldehyde by pyridinium chlorochromate (Corey's reagent) are reported. Michaelis-Menten behaviour is observed. The rate determining step appears to be the decomposition of a complex of benzaldehyde with PCC either through a loss of $H^+$ or $H^-$ ions.