scholarly journals THE USE OF THE ION ACTIVITY FUNCTION IN SOLUTION KINETICS. I. THE KINETICS OF HYDROCHLORIC ACID CATALYZED ESTER HYDROLYSIS.

1968 ◽  
Author(s):  
L. Leifer ◽  
F. Williams
Keyword(s):  
Hydrochloric Acid ◽  
Ester Hydrolysis ◽  
Ion Activity ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Solution Kinetics

Kinetics of cyclization of S-ethoxycarbonylmethylisothiouronium chloride to 2-imino-4-thiazolidone

1979 ◽  
Vol 44 (3) ◽  
pp. 912-917 ◽  
Author(s):  
Vladimír Macháček ◽  
Said A. El-bahai ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrochloric Acid ◽  
Dilute Hydrochloric Acid ◽  
Base Catalysis ◽  
General Base ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Rate Limiting ◽  
Kinetics Of

Kinetics of formation of 2-imino-4-thiazolidone from S-ethoxycarbonylmethylisothiouronium chloride has been studied in aqueous buffers and dilute hydrochloric acid. The reaction is subject to general base catalysis, the β value being 0.65. Its rate limiting step consists in acid-catalyzed splitting off of ethoxide ion from dipolar tetrahedral intermediate. At pH < 2 formation of this intermediate becomes rate-limiting; rate constant of its formation is 2 . 104 s-1.

Kinetics of acid-catalyzed cyclization of substituted hydantoinamides to substituted hydantoins

1987 ◽  
Vol 52 (8) ◽  
pp. 1999-2004 ◽  
Author(s):  
Jaromír Kaválek ◽  
Vladimír Macháček ◽  
Gabriela Svobodová ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrogen Atom ◽  
Nitrogen Atom ◽  
Hydrochloric Acid ◽  
Dissociation Constants ◽  
Amide Group ◽  
The Other ◽  
Methyl Group ◽  
Acid Catalyzed ◽  
Cyclization Rate ◽  
Kinetics Of

The kinetics of acid-catalyzed cyclization of the hydantoinamides type R3-N(5)H-CO-N(3)R2-CH2-CO-N(1)HR1 (R1, R2, R3 = H and/or CH3) has been studied in 0·5 to 5 mol l-1 hydrochloric acid. The cyclization rate is limited by the rate of the attack of nitrogen atom N(5) on the carbon atom of the protonated amide group. The dissociation constants of the protonated hydantoinamides and rate constants of their cyclizations have been determined. Replacement of hydrogen atom by methyl group at the N(5) nitrogen atom accelerates the cyclization about two times., the same substitution at N(3) accelerates about 50x, whereas at N(1) it results in a 300 fold retardation. With the hydantoinamides having R3 = CH3, the cyclization rate of the protonated hydantoinamide increases with increasing concentration of hydrochloric acid, whereas with the other derivatives this value is independent of the acid concentration.

The acid-catalyzed hydrolysis of methyl 2-chloro-2-deoxy-β-D-glucopyranoside

1967 ◽  
Vol 45 (5) ◽  
pp. 515-519 ◽  
Author(s):  
E. Buncel ◽  
P. R. Bradley
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solutions ◽  
Hydrochloric Acid Solutions ◽  
Mechanism Of Hydrolysis ◽  
Entropy Of Activation ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of the hydrolysis of methyl 2-chloro-2-deoxy-β-D-glucopyranoside have been determined in hydrochloric acid solutions over a range of acid concentrations and temperatures. Chloro substitution reduces the rate by a factor of 35 compared with the hydroxy analogue. Application of the Hammett criterion indicates a unimolecular (A-1) mechanism of hydrolysis, as does application of the Bunnett criterion. The entropy of activation, however, is considerably smaller than that observed for the hydrolysis of methyl β-d-glucopyranoside. This is interpreted as being indicative of partial A-2 character.

Kinetics and mechanism of solvolysis of substituted phenyl N-phenylbenzimidoesters

1987 ◽  
Vol 52 (5) ◽  
pp. 1285-1297
Author(s):  
Jaromír Kaválek ◽  
Ludmila Hejtmánková ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrochloric Acid ◽  
Kinetics And Mechanism ◽  
Reaction Products ◽  
Phenol Content ◽  
Aqueous Methanol ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Acid Catalyzed ◽  
Rate Limiting ◽  
Kinetics Of

Kinetics of hydrochloric acid-catalyzed solvolysis of substituted phenyl and methyl N-phenylbenzimidoesters have been studied in methanol, 50 vol. % aqueous methanol, and 50 vol. % aqueous tetrahydrofurane, and the composition of the reaction products has been determined. The rate-limiting step consists in addition of water or methanol to the protonated substrate. The reaction of methyl N-phenylbenzimidoester with both water and methanol and that of substituted phenyl N-phenylbenzimidoesters with methanol produce aniline, the ester (or orthoester) and the corresponding phenol. The reaction of substituted phenyl N-phenylbenzimidoesters with water gives both the neutral tetrahedral intermediate (which is decomposed into phenol and anilide) and the protonated intermediate (which produces aniline and the ester). At the same proton concentration the phenol content increases with increasing value of the σ constant of the substituent.

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.

Kinetic modelling of reactions for the synthesis of 2-methyl-5-ethyl pyridine

2021 ◽  
Author(s):  
Emanuele Moioli ◽  
Leo Schmid ◽  
Peter Wasserscheid ◽  
Hannsjoerg Freund
Keyword(s):  
Kinetic Modelling ◽  
Acid Catalyst ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Kinetics Of

The kinetics of the acid catalyzed reactions of acetaldehyde ammonia trimer (AAT) and paraldehyde (para) to 2-methyl-5-ethyl pyridine (MEP) in the presence of an acid catalyst were investigated systematically. A...

scholarly journals Kinetics of Substituted Bis- and Mono-azo Dyes as Corrosion Inhibitors for Aluminium in Hydrochloric Acid and Sodium Hydroxide Solutions

1999 ◽  
Vol 23 (7) ◽  
pp. 408-409
Author(s):  
Loutfy H. Madkour ◽  
R. M. Issa ◽  
I. M. El-Ghrabawy
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Azo Dyes ◽  
Thermodynamic Model ◽  
Corrosion Inhibitors ◽  
Kinetics Of ◽  
Alkaline Corrosion

This investigation is designed to apply an advanced kinetic–thermodynamic model on the data obtained from acidic and alkaline corrosion of aluminium using bis- and mono-azo dyes as corrosion inhibitors.

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