Mechanism of reactions of furans I: A kinetic study of the acid-catalyzed hydrolysis of furan and 2,5-dimethylfuran

2010 ◽  
Vol 83 (2) ◽  
pp. 167-176 ◽  
Author(s):  
E. J. Stamhuis ◽  
W. Drenth ◽  
H. van den Berg
Keyword(s):  
Kinetic Study ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Benzyl ethers of methyl α-D-glucopyranoside

1980 ◽  
Vol 45 (7) ◽  
pp. 1959-1963 ◽  
Author(s):  
Dušan Joniak ◽  
Božena Košíková ◽  
Ludmila Kosáková
Keyword(s):  
Kinetic Study ◽  
Spectrophotometric Determination ◽  
Reductive Cleavage ◽  
Ether Bond ◽  
Benzyl Ethers ◽  
Acid Catalyzed ◽  
Model Substances ◽  
Hydrolysis Of

Methyl 4-O-(3-methoxy-4-hydroxybenzyl) and methyl 4-O-(3,5-dimethoxy-4-hydroxybenzyl)-α-D-glucopyranoside and their 6-O-isomers were prepared as model substances for the ether lignin-saccharide bond by reductive cleavage of corresponding 4,6-O-benzylidene derivatives. Kinetic study of acid-catalyzed hydrolysis of the compounds prepared was carried out by spectrophotometric determination of the benzyl alcoholic groups set free, after their reaction with quinonemonochloroimide, and it showed the low stability of the p-hydroxybenzyl ether bond.

A kinetic study of the acid-catalyzed hydrolysis of some indolyl .beta.-D-glucopyranosides

1968 ◽  
Vol 33 (8) ◽  
pp. 3174-3178 ◽  
Author(s):  
Jerome P. Horwitz ◽  
Chittur V. Easwaran ◽  
Leon S. Kowalczyk
Keyword(s):  
Kinetic Study ◽  
Acid Catalyzed ◽  
Hydrolysis Of

scholarly journals Kinetic Study on the Acid-catalyzed Hydrolysis of Xylan

2012 ◽  
Vol 40 (6) ◽  
pp. 389-396
Author(s):  
Young-Jun Seo ◽  
Hong-Joo Lee ◽  
Jae-Won Lee
Keyword(s):  
Kinetic Study ◽  
Acid Catalyzed ◽  
Hydrolysis Of

scholarly journals Kinetic Study on the Acid-Catalyzed Hydrolysis of Cellulose to Levulinic Acid

2007 ◽  
Vol 46 (6) ◽  
pp. 1696-1708 ◽  
Author(s):  
B. Girisuta ◽  
L. P. B. M. Janssen ◽  
H. J. Heeres
Keyword(s):  
Kinetic Study ◽  
Levulinic Acid ◽  
Hydrolysis Of Cellulose ◽  
Acid Catalyzed ◽  
Hydrolysis Of

A KINETIC STUDY OF THE HYDROLYSIS OF BENZALANILINE

1953 ◽  
Vol 31 (4) ◽  
pp. 361-376 ◽  
Author(s):  
A. V. Willi ◽  
R. E. Robertson
Keyword(s):  
Kinetic Study ◽  
Acid Catalysis ◽  
Catalyst Concentration ◽  
Effect Of Substituents ◽  
General Acid ◽  
Acid Catalyzed ◽  
Interesting Special Case ◽  
Hydrolysis Of ◽  
Special Case

The rates of the acid catalyzed hydrolysis of a series of para substituted benzalanilines have been studied in 50/50 methanol–water in the presence of acetate buffers. Special and general acid catalysis were observed. The effect of para substituents on the rate is different for the charged and uncharged catalyst, and Hammett's relation cannot be applied. Similarly the effect of substituents on the Arrhenius constants for the two cases is different. The para dimethylamino derivative provides an interesting special case. For low buffer concentrations and in unbuffered solutions certain deviations were observed which show that the dependence of the rate on the catalyst concentration is more complicated than the equation[Formula: see text]

The effect of polymeric and model imidazolium halides on the rate of hydrolysis of 4-acetoxy-3-nitrobenzoic acid

1985 ◽  
Vol 50 (4) ◽  
pp. 845-853 ◽  
Author(s):  
Miloslav Šorm ◽  
Miloslav Procházka ◽  
Jaroslav Kálal
Keyword(s):  
Catalyst Concentration ◽  
Low Molecular Weight ◽  
Imidazolium Chloride ◽  
First Order ◽  
Nitrobenzoic Acid ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Hydrolysis Of ◽  
Ethanol In Water ◽  
Direct Attack

The course of hydrolysis of an ester, 4-acetoxy-3-nitrobenzoic acid catalyzed with poly(1-methyl-3-allylimidazolium bromide) (IIa), poly[l-methyl-3-(2-propinyl)imidazolium chloride] (IIb) and poly[l-methyl-3-(2-methacryloyloxyethyl)imidazolium bromide] (IIc) in a 28.5% aqueous ethanol was investigated as a function of pH and compared with low-molecular weight models, viz., l-methyl-3-alkylimidazolium bromides (the alkyl group being methyl, propyl, and hexyl, resp). Polymers IIb, IIc possessed a higher activity at pH above 9, while the models were more active at a lower pH with a maximum at pH 7.67. The catalytic activity at the higher pH is attributed to an attack by the OH- group, while at the lower pH it is assigned to a direct attack of water on the substrate. The rate of hydrolysis of 4-acetoxy-3-nitrobenzoic acid is proportional to the catalyst concentration [IIc] and proceeds as a first-order reaction. The hydrolysis depends on the composition of the solvent and was highest at 28.5% (vol.) of ethanol in water. The hydrolysis of a neutral ester, 4-nitrophenyl acetate, was not accelerated by IIc.

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.

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