26. The cumulative effect of substituents in an aromatic nucleus on reactions of the side-chain. Part II. The effect of chlorine as substituent on the reaction of benzoic acids with diazodiphenylmethane

1963 ◽  
pp. 178 ◽  
Author(s):  
A. Buckley ◽  
N. B. Chapman ◽  
J. Shorter
Keyword(s):  
Cumulative Effect ◽  
Aromatic Nucleus ◽  
Side Chain ◽  
Benzoic Acids ◽  
Effect Of Substituents ◽  
Effect Of Chlorine

scholarly journals Effect of side-chain length in lignin model compound on MnO2 oxidation: comparison of oxidations between C6-C2- and C6-C1-type compounds

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Shirong Sun ◽  
Tomoya Yokoyama
Keyword(s):  
Isotope Effects ◽  
Aromatic Nucleus ◽  
Side Chain ◽  
Direct Oxidation ◽  
Initial Oxidation ◽  
Methyl Group ◽  
Lignin Model Compound ◽  
Oxidation Rates ◽  
Kinetic Isotope ◽  
Lignin Model

AbstractMonomeric C6-C2-type lignin model compounds with a p-hydroxyphenyl (H), guaiacyl (G), syringyl (S), or p-ethylphenyl (E) nucleus (1-phenylethanol derivatives) were individually oxidized by MnO2 at a pH of 1.5 and room temperature. The results were compared with those of the corresponding C6-C1-type benzyl alcohol derivatives obtained in our recent report to examine the effect of the presence of the β-methyl group on the oxidation. The presence decelerated the oxidation regardless of the type of aromatic nucleus, although it did not change the order of the oxidation rates: G > S >> H > E. This deceleration results from the steric factor of the β-methyl group in the C6-C2-type compounds. The MnO2 oxidations of the corresponding C6-C2-type compounds deuterated at their α-(benzyl)positions showed that the magnitudes of the kinetic isotope effects are smaller than those observed in the oxidations of the corresponding C6-C1-type compounds, regardless of the type of aromatic nucleus. These smaller magnitudes suggest that the presence of the β-methyl group shifts the initial oxidation mode of MnO2 from direct oxidation of the benzyl position to one-electron oxidation of the aromatic nucleus. Only the S-type compounds afforded products via degradation of the aromatic nuclei.

scholarly journals Spectral Correlations in some Substituted Styryl (E)-4-((2-Oxopropyl)Diazenyl) Benzoic Acids

2014 ◽  
Vol 30 ◽  
pp. 33-43
Author(s):  
V. Sathiyendiran ◽  
K.G. Sekar ◽  
Ganesamoorthy Thirunarayanan ◽  
R. Arulkumaran ◽  
R. Sundararajan ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Statistical Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Benzoic Acids ◽  
Effect Of Substituents ◽  
Substituent Constants ◽  
Multi Linear Regression ◽  
Spectral Group

A series of titled compounds were prepared and analyzed their purities by literature method. The infrared and NMR spectral group frequencies of the compounds were assigned and correlated with Hammett substituent constants, F and R constants using single and multi linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral frequencies was discussed.

Biosynthese von p-Hydroxybenzoesäure und anderer Benzoesäuren in höheren Pflanzen

1964 ◽  
Vol 19 (5) ◽  
pp. 398-405 ◽  
Author(s):  
M. H. Zenk ◽  
G. Müller
Keyword(s):  
Benzoic Acid ◽  
Protocatechuic Acid ◽  
Higher Plants ◽  
Side Chain ◽  
Hydroxybenzoic Acid ◽  
Benzoic Acids ◽  
Coumaric Acid ◽  
Cinnamic Acids ◽  
Feeding Experiments ◽  
Catalpa Ovata

Feeding experiments with glucose- (2-14C), phenylalanine- (3-14C), tyrosine- (3-14C) and p-coumaric acid- (3-14C) showed that the latter three substances are incorporated in good yields into p-hydroxybenzoic acid in leaves of Catalpa ovata. Kinetic experiments showed that p-hydroxybenzoic acid is formed from phenylalanine via p-coumaric acid and the subsequent β-oxidation of the side chain. p-Hydroxybenzoic acid can also be synthetised by hydroxylation of benzoic acid, but this does not seem to be the biosynthetic route in Catalpa.Phenylalanine- (3-14C) is also incorporated into benzoic acid, protocatechuic acid, and vanillic acid by different plants; the radioactivity of the β-C atom of the amino acid was found in each case to be located in the carboxyl group of the C6 — C1 acid. This suggests that in higher plants the benzoic acids are formed from the corresponding cinnamic acids via β-oxidation.

scholarly journals Grids to Illustrate Induction and Resonance Effects: Aromatic Acidity and Basicity

2020 ◽  
Author(s):  
Guy Lamoureux ◽  
Carlos Árias-Alvarez
Keyword(s):  
Educational Process ◽  
Benzoic Acids ◽  
Resonance Effects ◽  
Effect Of Substituents ◽  
Acidity And Basicity

The effect of substituents on the acidity of benzoic acids and anilines has been organized in grids to demonstrate the inductive and resonance effects. The relation between structure and pKa is emphasized by a new educational process: the Search-Organize-Predict (SOP) procedure.

scholarly journals The structure and reactivity of the halogenobenzens

1946 ◽  
Vol 185 (1000) ◽  
pp. 119-126
Keyword(s):  
Transition State ◽  
Charge Distribution ◽  
Aromatic Compounds ◽  
Inductive Effect ◽  
Dipole Moments ◽  
Aromatic Nucleus ◽  
Side Chain ◽  
Chain Reactions ◽  
State Resonance ◽  
Inductive Effects

The structure of the halogenobenzenes is described in terms of an inductive effect acting on the meta -positions and polarization between neighbouring atoms, in addition to the well-recognized mesomeric and inductive effects at the ortho - and para -positions. Data on the side-chain reactions of aromatic compounds are correlated with those on nitration (with recognition of the effect of transition-state resonance in the latter case) to provide estimates of the charge distribution in the aromatic nucleus. The dipole moments of the halogenobenzenes are calculated.

Synthesis of perbromobenzoic acids and perbromobenzenes from aromatic carboxylic acids by permercuration and bromodemercuration

1977 ◽  
Vol 30 (2) ◽  
pp. 293 ◽  
Author(s):  
GB Deacon ◽  
GJ Farquharson
Keyword(s):  
Thermal Decomposition ◽  
Carboxylic Acids ◽  
Carboxyl Group ◽  
Benzoic Acids ◽  
Similar Treatment ◽  
Aromatic Carboxylic Acids ◽  
Effect Of Substituents

Permercuration of the benzoic acids XC6H4CO2H (X = o-Me, F, Cl, or Br; m- Me, F, Cl, Br, CF3, NO2 or OMe; or p-Me, F, Cl, Br, CF3 or NO2) and 2,6- X2C6H3CO2H (X = Me, Cl, or Br) with molten mercuric trifluoroacetate at c. 180-245° followed by bromodemercuration gave the corresponding perbromobenzoic acids XC6Br4CO2H or 2,6-X2C6Br3CO2H, together with the corresponding perbromobenzenes C6Br5X or m-X2C6Br4 which were formed owing to decarboxylation under permercuration conditions. Similar treatment of the acids XC6H4CO2H (X = o-NO2, CF3, or OMe; or p-OMe) and 2,6-F2C6H3CO2H gave only the appropriate perbromobenzenes. Possible mechanisms for permercuration induced decarboxylation are proposed on the basis of the effect of substituents on yields of perbromobenzoic acids and perbromobenzenes. Decarboxylation occurs more widely under permercuration conditions than on pyrolysis of mercuric carboxylates. Regiospecific mercuration meta to the carboxyl group and not decarboxylation occurred on thermal decomposition of mercuric p-methoxybenzoate.

Barrier to Internal Rotation in 2,6-Dichlorobenzal Iodide and some α,α′-m-Xylyl Halides. Experimental Evidence for the Transition State Conformation in Benzal Halides

1974 ◽  
Vol 52 (13) ◽  
pp. 2414-2420 ◽  
Author(s):  
James Peeling ◽  
J. Brian Rowbotham ◽  
Ludger Ernst ◽  
Ted Schaefer
Keyword(s):  
Magnetic Resonance ◽  
Transition State ◽  
Experimental Evidence ◽  
Internal Rotation ◽  
Proton Magnetic Resonance ◽  
Rotational State ◽  
Aromatic Nucleus ◽  
Side Chain ◽  
Barriers To Internal Rotation

The barriers to internal rotation in the α,α′-di-X-2,4,5,6-dichloro-m-xylenes (X = Cl, Br, I ) are determined by proton magnetic resonance bandshape analyses. Their magnitudes are experimental evidence for the calculated conformation of the activated rotational state of the benzal halides, in which the C—H bond of the side chain is predicted to lie in a plane perpendicular to the aromatic nucleus. The synthesis and the barrier to rotation in 2,6-dichlorobenzal iodide are reported.

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