Vapor Pressures and Phase Diagrams of Two Methyl Esters of Substituted Benzoic Acids

2011 ◽  
Vol 56 (12) ◽  
pp. 4862-4867 ◽  
Author(s):  
Ana R. R. P. Almeida ◽  
Manuel J. S. Monte
Keyword(s):  
Phase Diagrams ◽  
Methyl Esters ◽  
Benzoic Acids ◽  
Vapor Pressures ◽  
Substituted Benzoic Acids

Correction. Methyl Esters of Substituted Benzoic Acids

1952 ◽  
Vol 74 (24) ◽  
pp. 6319-6319
Author(s):  
Robert West ◽  
Severo Ornstein ◽  
Donald McKee ◽  
Robert Layzer
Keyword(s):  
Methyl Esters ◽  
Benzoic Acids ◽  
Substituted Benzoic Acids

13C n.m.r. studies. X. 13C spectra of some substituted methyl benzoates

1967 ◽  
Vol 45 (3) ◽  
pp. 233-238 ◽  
Author(s):  
K. S. Dhami ◽  
J. B. Stothers
Keyword(s):  
Aromatic Ring ◽  
Chemical Shifts ◽  
Methyl Esters ◽  
Benzoic Acids ◽  
Similar Series ◽  
Substituted Benzoic Acids

The 13C spectra of the methyl esters of 20 substituted benzoic acids have been recorded, and the chemical shifts of the carbon nuclei of the carbomethoxyl group and aromatic ring have been measured. These shielding results are discussed and compared with the corresponding data for similar series of acetophenones and anisoles. Some evidence of steric inhibition of conjugation is presented for certain diortho-substituted examples.

Kinetics and Mechanism of Decomposition of 1,3-Bis(4-methylphenyl)triazene Catalyzed with Substituted Benzoic Acids in 25% Aqueous Methanol-General or Specific Catalysis?

1994 ◽  
Vol 59 (9) ◽  
pp. 2029-2041
Author(s):  
Oldřich Pytela ◽  
Taťjana Nevěčná
Keyword(s):  
Benzoic Acids ◽  
Hammett Equation ◽  
Aqueous Methanol ◽  
Mechanism Of Decomposition ◽  
Kinetics Of Decomposition ◽  
Independent Variable ◽  
Amino Derivatives ◽  
Substituted Benzoic Acids ◽  
The Individual ◽  
Kinetics Of

The kinetics of decomposition of 1,3-bis(4-methylphenyl)triazene catalyzed with 13 substituted benzoic acids of various concentrations have been measured in 25 vol.% aqueous methanol at 25.0 °C. The rate constants observed (297 data) have be used as values of independent variable in a series of models of the catalyzed decomposition. For the catalytic particles were considered the undissociated acid, its conjugated base, and the proton in both the specific and general catalyses. Some models presumed formation of reactive or nonreactive complexes of the individual reactants. The substituent effect is described by the Hammett equation. The statistically best model in which the observed rate constant is a superposition of a term describing the dependence on proton concentration and a term describing the dependence on the product of concentrations of proton and conjugated base is valid with the presumption of complete proton transfer from the catalyst acid to substrate, which has been proved. The behaviour of 4-dimethylamino, 4-amino, and 3-amino derivatives is anomalous (lower catalytic activity as compared with benzoic acid). This supports the presumed participation of conjugated base in the title process.

Kinetic study of hydrolysis of benzoates. part xxvii. ortho substituent effect in alkaline hydrolysis of phenyl esters of substituted benzoic acids in aqueous Bu4NBr

2009 ◽  
Vol 74 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Signe Vahur ◽  
Oksana Travnikova ◽  
Ilmar A. Koppel
Keyword(s):  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Pure Water ◽  
Substituent Effects ◽  
Benzoic Acids ◽  
Resonance Effects ◽  
The Media ◽  
Substituted Benzoic Acids ◽  
Hydrolysis Of ◽  
Ortho Substituent

The second-order rate constants k (in dm3 mol–1 s–1) for alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5, have been measured spectrophotometrically in aqueous 0.5 and 2.25 M Bu4NBr at 25 °C. The substituent effects for para and meta derivatives were described using the Hammett relationship. For the ortho derivatives the Charton equation was used. For ortho-substituted esters two steric scales were involved: the EsB and the Charton steric (υ) constants. When going from pure water to aqueous 0.5 and 2.25 M Bu4NBr, the meta and para polar effects, the ortho inductive and resonance effects in alkaline hydrolysis of phenyl esters of substituted benzoic acids, became stronger nearly to the same extent as found for alkaline hydrolysis of C6H5CO2C6H4-X. The steric term of ortho-substituted esters was almost independent of the media considered. The rate constants of alkaline hydrolysis of ortho-, meta- and para-substituted phenyl benzoates (X-C6H4CO2C6H5, C6H5CO2C6H4-X) and alkyl benzoates, C6H5CO2R, in water, 0.5 and 2.25 M Bu4NBr were correlated with the corresponding IR stretching frequencies of carbonyl group, (ΔνCO)X.

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