Alkaline hydrolysis of monomethyl esters of maleic and fumaric acids

1983 ◽  
Vol 48 (5) ◽  
pp. 1305-1313
Author(s):  
Petr Komadel ◽  
Vladislav Holba ◽  
Štefan Truchlik
Keyword(s):  
Activation Energy ◽  
Ionic Strength ◽  
Alkaline Hydrolysis ◽  
Reaction Medium ◽  
Measured Data ◽  
Interaction Energies ◽  
Mutual Compensation ◽  
Experimental Activation Energy ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of alkaline hydrolysis of maleic and fumaric acids monomethyl esters were studied as function of the temperature, ionic strength, and relative permittivity of the reaction medium. Electrostatic and nonelectrostatic contributions of the interaction energies of reacting species were calculated from the measured data and compared with the experimental activation energy values. The dependence of the rate constant on the temperature brings an evidence for the mutual compensation of the electrostatic and nonelectrostatic effects.

Kinetics of hydrolysis of peroxodisulphate ions in acidic medium to peroxomonosulphuric acid

1981 ◽  
Vol 46 (5) ◽  
pp. 1229-1236 ◽  
Author(s):  
Jan Balej ◽  
Milada Thumová
Keyword(s):  
Ionic Strength ◽  
Rate Constants ◽  
Acidic Medium ◽  
Measured Data ◽  
Molar Ratios ◽  
Starting Solution ◽  
Kinetics Of Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

The rate of hydrolysis of S2O82- ions in acidic medium to peroxomonosulphuric acid was measured at 20 and 30 °C. The composition of the starting solution corresponded to the anolyte flowing out from an electrolyser for production of this acid or its ammonium salt at various degrees of conversion and starting molar ratios of sulphuric acid to ammonium sulphate. The measured data served to calculate the rate constants at both temperatures on the basis of the earlier proposed mechanism of the hydrolysis, and their dependence on the ionic strength was studied.

KINETICS OF THE ALKALINE HYDROLYSIS OF PROPIONITRILE

1942 ◽  
Vol 20b (9) ◽  
pp. 185-188 ◽  
Author(s):  
B. S. Rabinovitch ◽  
C. A. Winkler
Keyword(s):  
Activation Energy ◽  
Sodium Hydroxide ◽  
Alkaline Hydrolysis ◽  
Aqueous Sodium Hydroxide ◽  
Alkali Concentration ◽  
Aqueous Sodium ◽  
Velocity Constant ◽  
Total Ammonia ◽  
Kinetics Of ◽  
Hydrolysis Of

Some contradictory points recorded for the alkaline hydrolysis of nitriles have been clarified by a study of propionitrile hydrolysis in aqueous sodium hydroxide solutions of concentration 0.3 to 4 N. It has been shown that the rate of alkaline hydrolysis of propionitrile is given by the rate of formation of total ammonia and intermediate amide and not by that of ammonia alone. The relative rates of propionitrile and propionamide hydrolysis were found to be approximately 1:10 over the whole alkali concentration range. The bimolecular velocity constant is essentially independent of alkali concentration. An activation energy of 20,300 cal. was determined for the reaction in 0.65 N alkali.

Kinetics of alkaline hydrolysis of diphenic and terephthalic acid monomethyl esters

1980 ◽  
Vol 45 (1) ◽  
pp. 255-262 ◽  
Author(s):  
Vladislav Holba ◽  
Ján Benko ◽  
Jana Kozánková
Keyword(s):  
Ionic Strength ◽  
Alkaline Hydrolysis ◽  
Terephthalic Acid ◽  
Activation Parameters ◽  
Diphenic Acid ◽  
Temperature Dependences ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Specific Influence ◽  
Monomethyl Ester

The dependence of the rate constant of alkaline hydrolysis of diphenic acid monomethyl ester and terephthalic acid monomethyl ester on ionic strength and temperature was studied together with the specific influence of some electrolytes on the reaction rate. Thermodynamic activation parameters extrapolated to zero ionic strength and critical interionic distances of reacting ions were calculated from the temperature dependences of the rate constants.

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.

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.

Effect of Medium on Reactivity for Alkaline Hydrolysis of p-Nitrophenyl Acetate and S-p-Nitrophenyl Thioacetate in DMSO-H2O Mixtures of Varying Compositions: Ground State and Transition State Contributions

2021 ◽  
Author(s):  
Ik-Hwan Um ◽  
Seungjae Kim
Keyword(s):  
Transition State ◽  
Alkaline Hydrolysis ◽  
Ground State ◽  
Rate Constants ◽  
Kinetic Data ◽  
Reaction Medium ◽  
Stepwise Mechanism ◽  
Rate Determining Step ◽  
Leaving Group ◽  
Hydrolysis Of

Second-order rate constants (kN) for reactions of p-nitrophenyl acetate (1) and S-p-nitrophenyl thioacetate (2) with OH‒ have been measured spectrophotometrically in DMSO-H2O mixtures of varying compositions at 25.0 ± 0.1 oC. The kN value increases from 11.6 to 32,800 M‒1s‒1 for the reactions of 1 and from 5.90 to 190,000 M‒1s‒1 for those of 2 as the reaction medium changes from H2O to 80 mol % DMSO, indicating that the effect of medium on reactivity is more remarkable for the reactions of 2 than for those of 1. Although 2 possesses a better leaving group than 1, the former is less reactive than the latter by a factor of 2 in H2O. This implies that expulsion of the leaving group is not advanced in the rate-determining transition state (TS), i.e., the reactions of 1 and 2 with OH‒ proceed through a stepwise mechanism, in which expulsion of the leaving group from the addition intermediate occurs after the rate-determining step (RDS). Addition of DMSO to H2O would destabilize OH‒ through electronic repulsion between the anion and the negative-dipole end in DMSO. However, destabilization of OH‒ in the ground state (GS) is not solely responsible for the remarkably enhanced reactivity upon addition of DMSO to the medium. The effect of medium on reactivity has been dissected into the GS and TS contributions through combination of the kinetic data with the transfer enthalpies (ΔΔHtr) from H2O to DMSO-H2O mixtures for OH‒ ion.

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