Substituent Effects on the Base-Catalysed Hydrolysis of Phenyl Esters of ortho-Substituted Benzoic Acids

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Title:Substituent Effects on the Base-Catalysed Hydrolysis of Phenyl Esters of ortho-Substituted Benzoic Acids
Creators:
Bauerová, Ingrid
Ludwig, Miroslav
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 66, 5, pp. 770-784
Uncontrolled Keywords:Chemometrics, Kinetics, <i>ortho</i>-Effect, Esters, AISE theory, Base-catalysed hydrolysis, Hammett equation, Substituent effects, Benzoic acids

Abstract

Fourteen model phenyl esters of 2-substituted benzoic acids were synthesised. Structures and purity of model compounds were confirmed by <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy, as well as by HPLC and elemental analysis. Kinetics of base-catalysed hydrolysis of model phenyl esters occurring by the BAc2 mechanism were measured by UV spectrophotometry in 50% (v/v) aqueous dimethyl sulfoxide solutions at 25 °C under pseudo-first-order reaction conditions (<i>c</i>(NaOH) = 0.001-1.0 mol l<sup>-1</sup>). Linear relation between <i>J</i><sub>-</sub><sup>E</sup> and log <i>k</i><sub>obs</sub> with the slope close to unity was found for all model compounds. Neither one-parameter nor multiparameter Hammett-type description of variability of experimental data obtained for phenyl esters of 2-substituted benzoic acids was found. Two groups (conjugating and non-conjugating) were created by division of <i>ortho</i>-substituents in <i>ortho</i>-position using the AISE theory, based on their interaction with the reaction centre. <p>

Title:Substituent Effects on the Base-Catalysed Hydrolysis of Phenyl Esters of ortho-Substituted Benzoic Acids
Creators:
Bauerová, Ingrid
Ludwig, Miroslav
Uncontrolled Keywords:Chemometrics, Kinetics, <i>ortho</i>-Effect, Esters, AISE theory, Base-catalysed hydrolysis, Hammett equation, Substituent effects, Benzoic acids
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:66
Number:5
Page Range:pp. 770-784
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20010770UNSPECIFIED
ID Code:1822
Item Type:Article
Deposited On:06 Feb 2009 17:13
Last Modified:06 Feb 2009 16:13

Citation

Bauerová, Ingrid; Ludwig, Miroslav (2001) Substituent Effects on the Base-Catalysed Hydrolysis of Phenyl Esters of ortho-Substituted Benzoic Acids. Collection of Czechoslovak Chemical Communications, 66 (5). pp. 770-784. ISSN 0010-0765

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