THE TRANSMISSION OF POLAR EFFECTS: PART III. THE KINETICS OF THE ACID-CATALYZED ESTERIFICATION OF 3-SUBSTITUTED ACRYLIC ACIDS AND THE ALKALINE HYDROLYSIS OF THE METHYL ESTERS

1966 ◽  
Vol 44 (6) ◽  
pp. 661-669 ◽  
Author(s):  
Keith Bowden
Keyword(s):  
Alkaline Hydrolysis ◽  
Methyl Esters ◽  
Rate Coefficients ◽  
Steric Effects ◽  
Trans Isomers ◽  
Electrostatic Effect ◽  
Acid Catalyzed ◽  
Acrylic Acids ◽  
Kinetics Of ◽  
Hydrolysis Of

The rate coefficients for the acid-catalyzed esterification in methanol at 35.0° of fourteen 3-substituted acrylic acids have been determined. Rate coefficients have also been determined for the alkaline hydrolysis in 70% v/v dioxin–water at 18.8° of 13 methyl esters and the carbonyl-stretching frequencies of the esters have been examined. The effect of trans-substitution is assessed by use of the Hammett equation. In the alkaline hydrolysis, the transmission of polar effects is approximately 1.9 that of the meta- and para-substituted benzoates. An analysis of the steric effects in the cis-isomers in both reactions shows that the steric effects of the halogeno-substituents in the two reactions differ and an explanation is offered. The application of the Taft–Ingold equation to ortho-substituted benzoates is criticized. The carbonyl-stretching frequencies of the cis-halogeno-esters exhibit a shift of +8 cm−1 compared with the trans-isomers; this shift is attributed to an electrostatic effect.

The Kinetics of the Acid-Catalyzed Hydrolysis of the Methyl Esters of Cyclo-hexanedicarboxylic Acids1

1961 ◽  
Vol 26 (5) ◽  
pp. 1408-1410 ◽  
Author(s):  
HILTON A. SMITH ◽  
KENNETH G. SCROGHAM ◽  
BILLY L. STUMP
Keyword(s):  
Methyl Esters ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Hydrolysis Of

Transmission of polar effects. Part XI. Polar and steric effects in the reactions of arylaliphatic carboxylic acids

1969 ◽  
Vol 47 (15) ◽  
pp. 2775-2779 ◽  
Author(s):  
Keith Bowden ◽  
R. C. Young
Keyword(s):  
Carboxylic Acids ◽  
Alkaline Hydrolysis ◽  
Rate Coefficients ◽  
Steric Effects ◽  
Measured Rate ◽  
Substituent Constants ◽  
Esterification Rate ◽  
Acid Catalyzed

The rate coefficients for the reaction with diazodiphenylmethane in ethanol at 30° and the acid-catalyzed esterification with methanol at 60° of a number of arylaliphatic carboxylic acids and their pKa values in 80% 2-methoxyethanol–water have been measured. Rate coefficients have also been measured for the alkaline hydrolysis in 70% dioxan–water of their 2-diethylaminoethyl esters at 45°. The pKa values and diazodiphenylmethane esterification rate coefficients were also measured for a series of 2-substituted fluorene-9-carboxylic acids. The latter results have been correlated by Hammett equations and the transmission of polar effects in fluorene is discussed. Polar and steric substituent constants are evaluated for the arylaliphatic systems. These values are used to successfully correlate the hydrolysis and ionization reactions using the Taft–Ingold equation.

Influence of medium on alkaline hydrolysis of succinic acid monomethyl and monopropyl esters

1980 ◽  
Vol 45 (11) ◽  
pp. 2873-2882
Author(s):  
Vladislav Holba ◽  
Ján Benko
Keyword(s):  
Succinic Acid ◽  
Kinetic Parameters ◽  
Alkaline Hydrolysis ◽  
Specific Interactions ◽  
Nonaqueous Media ◽  
The Media ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of alkaline hydrolysis of succinic acid monomethyl and monopropyl esters were studied in mixed aqueous-nonaqueous media at various temperatures and ionic strengths. The results of measurements are discussed in terms of electrostatic and specific interactions between the reactants and other components of the reaction mixture. The kinetic parameters in the media under study are related to the influence of the cosolvent on the solvation sphere of the reactants.

Cyclization and acid-catalyzed hydrolysis of O-benzoylbenzamidoximes

1986 ◽  
Vol 51 (12) ◽  
pp. 2786-2797
Author(s):  
František Grambal ◽  
Jan Lasovský
Keyword(s):  
Reaction Rate ◽  
Kinetic Isotope ◽  
Acid Base Equilibrium ◽  
Mineral Acids ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Ph Scale ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

The Kinetics of the Acidic and Alkaline Hydrolysis of Ethyl Thionbenzoate

1963 ◽  
Vol 28 (10) ◽  
pp. 2825-2828 ◽  
Author(s):  
Stanley G. Smith ◽  
Marion O'Leary
Keyword(s):  
Alkaline Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

scholarly journals Isothermal and non-isothermal kinetics of hydrolysis of 1-[2-(2- pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]- perhydroazepinium chloride (BK 129)

2013 ◽  
Vol 60 (2) ◽  
pp. 43-48
Author(s):  
Stankovičová M. ◽  
Bezáková Ž. ◽  
Beňo P. ◽  
Húšťavová P.
Keyword(s):  
Biological Activity ◽  
Alkaline Hydrolysis ◽  
Functional Group ◽  
Isothermal Kinetics ◽  
Basic Part ◽  
Buffer Solutions ◽  
Kinetics Of Hydrolysis ◽  
Short Time ◽  
Kinetics Of ◽  
Hydrolysis Of

Abstract The substance BK 129 - 1-[2-(2-pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]-perhydroazepinium chloride was prepared in terms of influence of the connecting chain between the carbamate functional group and the basic part of molecule on biological activity. Such a structural feature is important with regard to its stability. In this work we determined the rate constants of alkaline hydrolysis of this compound at increased temperature under isothermal and non-isothermal conditions. The hydrolysis was also performed in buffer solutions with the purpose of evaluating its stability. Non-isothermal tests of stability enable to reduce the number of analyses. The necessary data for stability of compound are in this way achieved in a short time.

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