INFLUENCE OF SUBSTITUTES ON THE RATE OF THE REACTION OF ORTHOSUBSTITUTED BENZOIC ACIDS WTH ANILINE, CATALYZED BY POLYBUTOXYTITANATES

The polybutoxytitanates catalysis of aniline acylation by orthosubstituted benzoic acids leads to the production of substituted benzanilides. Catalytic rate constants of the second order reaction (the first with respect to aniline and ortho-substituted benzoic acid; boiling ortho=xylene, 145°C) correlate well according to the Hammett and Bronsted equations with straight line segments with ρ=1.93 and α=0.66, in contrast to the reaction of aniline with meta- and parasubstituted benzoic acids and substituted anilines with benzoic acid. This dependence drops out 2=nitrobenzoic and 1=naphthoic acids, which have relatively low reactivity and the greatest steric hindrances both for nucleophilic attack by aniline and for possible coordination with catalytically active centers of the corresponding ortho-substituted titanium polybutoxybenzoates formed in situ. Based on these data, the previously proposed mechanism of bifunctional catalysis due to titanium polybutoxybenzoates and their complexes with meta- and parasubstitutedbenzanilides was supplemented by the possibility of the steric inhibition of reaction by the most bulky substituents and chelate structures formation of orthosubstituted benzoic acids and their anilides with individual titanium atoms of the catalyst, as well as the simultaneous H-bonding of the amino group hydrogen atoms of aniline, which leads to its activation to a nucleophilic attack, with a carbonyl group and an orthopositioned substituent of the orthobenzoate ligand in the coordination sphere of titanium. Taking into account such chelation and steric barriers, as well as inhibition of acid catalysis due to the formation of the imide form of anilides, containing electron-withdrawing substituents, the equations for the rate constants of the catalytic reaction of ortho-substituted benzoic acids with aniline are derived, corresponding to the experimentally obtained Hammett dependence.

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INFLUENCE OF SUBSTITUTES ON THE RATE OF THE REACTION OF META- АND PARASUBSTITUTED BENZOIC ACIDS WTH ANILINE, CATALYZED BY POLYBUTOXYTITANATES

Ukrainian Chemistry Journal ◽

10.33609/2708-129x.86.6.2020.108-131 ◽

2020 ◽

Vol 86 (6) ◽

pp. 108-131

Author(s):

Leon Shteynberg

Keyword(s):

Benzoic Acid ◽

Carbonyl Group ◽

Titanium Atom ◽

Nucleophilic Attack ◽

Substituted Anilines ◽

Hydrogen Atoms ◽

Phthalic Acids ◽

Straight Lines ◽

Nucleophilic Center

The polybutoxytitanates catalysis of acylation of anilines by meta- and parasubstituted benzoic acid results in substituted benzanilides. The rate constants of this second-order reaction (the first in terms of aniline and substituted benzoic acid; boiling ortho-xylene, 145 °С) correlates well according to the Hammett equation with two straight lines for individual groups of substituents with ρ = 1.76 (electron donors) and 0.12 (electron acceptors). Oxybenzoic and phthalic acids, that do not react with aniline and inhibit the interaction of the latter with benzoic acid, fall out of this dependence. Based on these data, as well as the results of a previous studies of the interaction of substituted anilines with a benzoic acid made under comparable conditions, a mechanism of bifunctional catalysis due to the formation of titanium polybutoxybenzoates in the first minutes of the reaction in situ — the true catalysts of the process, is proposed. The nucleophilic center of the catalyst can be represented by the carbonyl group of a substituted benzoate bound to a titanium atom, forming an H-bond with hydrogen atoms of the amino group of aniline, thus activated to react with a substituted benzoic acid. The titanium atoms of polytitanate (coordination catalysis) and their complexes with the resulting substituted benzanilides (acid catalysis) can act as the electrophilic center of a catalyst that activates the carbonyl group of a substituted benzoic acid to nucleophilic attack by aniline. A titanium atom bound to a substituted benzoate exhibits, depending on the nature of the substituent, various catalytic activity.

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

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc2008019 ◽

2009 ◽

Vol 74 (1) ◽

pp. 29-42 ◽

Cited By ~ 9

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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Mixed-dimer formation in binary systems of 4-substituted benzoic acids and structure considerations

Canadian Journal of Chemistry ◽

10.1139/v08-008 ◽

2008 ◽

Vol 86 (6) ◽

pp. 525-532 ◽

Cited By ~ 6

Author(s):

Maren Roman ◽

Annett Kaeding-Koppers ◽

Peter Zugenmaier

Keyword(s):

Benzoic Acid ◽

Crystalline Phase ◽

Liquid Crystalline ◽

Binary Systems ◽

Benzoic Acids ◽

Dimer Formation ◽

Crystalline Phases ◽

Cholesteric Phase ◽

Liquid Crystalline Phases ◽

Substituted Benzoic Acids

The phase behavior of binary systems of 4-substituted benzoic acids is governed by the formation of mixed dimers. This study was conducted to determine the effect of the components’ structural difference on mixed-dimer formation in crystalline and liquid-crystalline phases. The phase diagrams of two systems, with 4-[(S)-(–)-2-methylbutoxy]benzoic acid (MBOBA) as one component and 4-(hex-5-enoxy)benzoic acid (HOBA) and 4-(dec-9-enoxy)benzoic acid (DOBA), respectively, as the second component, were determined by differential scanning calorimetry, polarized-light microscopy, and X-ray diffraction. The MBOBA-HOBA system exhibited a cholesteric phase, two solid solutions, and above 58 °C for compositions between 40 and 80 mol% HOBA a crystalline phase of mixed dimers. The MBOBA-DOBA system showed a crystalline phase of mixed dimers at all compositions, a cholesteric phase, and a twisted smectic C phase, which was dominated by mixed dimers at 60 and 70 mol% DOBA. We conclude that liquid-crystalline phases are generally dominated by mixed dimers, but in crystalline phases the formation of mixed dimers is promoted by a greater difference in molecular structure. The crystal structure of two of the pure compounds MBOBA and DOBA and comparable compounds have been determined for an evaluation of the arrangements of the molecules in the crystal and liquid-crystalline state.Key words: benzoic acid, crystal arrangement, phase diagrams, liquid crystal.

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Electrochemical Reduction of Benzoic Acid and Substituted Benzoic Acids in Some Room Temperature Ionic Liquids

The Journal of Physical Chemistry C ◽

10.1021/jp802996q ◽

2008 ◽

Vol 112 (33) ◽

pp. 12966-12973 ◽

Cited By ~ 34

Author(s):

Debbie S. Silvester ◽

Weisi He ◽

Leigh Aldous ◽

Christopher Hardacre ◽

Richard G. Compton

Keyword(s):

Ionic Liquids ◽

Benzoic Acid ◽

Electrochemical Reduction ◽

Room Temperature ◽

Room Temperature Ionic Liquids ◽

Benzoic Acids ◽

Substituted Benzoic Acids

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Prediction of ortho substituent effect in alkaline hydrolysis of phenyl esters of substituted benzoic acids in aqueous acetonitrile

Open Chemistry ◽

10.2478/s11532-013-0321-5 ◽

2013 ◽

Vol 11 (12) ◽

pp. 1964-1975 ◽

Cited By ~ 1

Author(s):

Vilve Nummert ◽

Mare Piirsalu ◽

Ilmar Koppel

Keyword(s):

Alkaline Hydrolysis ◽

Rate Constants ◽

Substituent Effect ◽

Substituent Effects ◽

Benzoic Acids ◽

Aqueous Acetonitrile ◽

Substituent Constants ◽

Substituted Benzoic Acids ◽

Hydrolysis Of ◽

Ortho Substituent

AbstractThe second-order rate constants k for the alkaline hydrolysis of phenyl esters of meta-, para- and ortho-substituted benzoic acids, X-C6H4CO2C6H5, in aqueous 50.9% acetonitrile have been measured spectrophotometrically at 25°C. The log k values for meta and para derivatives correlated well with the Hammett σm,p substituent constants. The log k values for ortho-substituted phenyl benzoates showed good correlations with the Charton equation, containing the inductive, σI, resonance, σ○ R, and steric, E s B, and Charton υ substituent constants. For ortho derivatives the predicted (log k X)calc values were calculated with equation (log k ortho)calc = (log k H AN)exp + 0.059 + 2.19σI + 0.304σ○ R + 2.79E s B − 0.0164ΔEσI — 0.0854ΔEσ○ R, where DE is the solvent electrophilicity, ΔE = E AN — E H20 = −5.84 for aqueous 50.9% acetonitrile. The predicted (log k X)calc values for phenyl ortho-, meta- and para-substituted benzoates in aqueous 50.9% acetonitrile at 25°C precisely coincided with the experimental log k values determined in the present work.The substituent effects from the benzoyl moiety and aryl moiety were compared by correlating the log k values for the alkaline hydrolysis of phenyl esters of substituted benzoic acids, X-C6H4CO2C6H5, in various media with the corresponding log k values for substituted phenyl benzoates, C6H5CO2C6H4-X.

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