Hydrolysis of amides. I. The hydrolysis of acetamide and chloroacetamide in dilute acid

1965 ◽  
Vol 18 (6) ◽  
pp. 795
Author(s):  
PD Bolton ◽  
IR Wilson
Keyword(s):  
Recent Work ◽  
Acidic Solution ◽  
Kinetic Studies ◽  
Systematic Errors ◽  
Dilute Acid ◽  
Compound A ◽  
Satisfactory Correlation ◽  
Entropy Of Activation ◽  
Consistent Treatment ◽  
Hydrolysis Of

Kinetic studies of the hydrolysis of acetamide in dilute acidic solution are reported. These reveal the presence of systematic errors in some previous work on this compound. A consistent treatment is given, leading to values of the energy and entropy of activation (at 75�) of 19.8 kcal and -17.8 e.u. and satisfactory correlation of most previous results. Similar defects are present in recent work on chloroacetamide hydrolysis and the same approach is used in a reinterpretation.

Micellar catalysis of organic reactions. XIV. Hydrolysis of some 1,4-Benzodiazepin-2-one drugs in acidic solution

1984 ◽  
Vol 37 (9) ◽  
pp. 1895 ◽  
Author(s):  
TJ Broxton ◽  
T Ryan ◽  
SR Morrison
Keyword(s):  
Acid Concentration ◽  
Acidic Solution ◽  
Sodium Dodecyl ◽  
Kinetic Studies ◽  
Micellar Catalysis ◽  
Amide Bond ◽  
First Order ◽  
Amide Hydrolysis ◽  
Hydrolysis Of ◽  
Azomethine Bond

Kinetic studies of the acidic hydrolysis of diazepam and nitrazepam were carried out in the presence of micelles of sodium dodecyl sulfate (sds). The hydrolysis of diazepam was shown to occur with biphasic kinetics. This is consistent with initial hydrolysis of the azomethine bond followed by very slow hydrolysis of the amide bond as found for hydrolysis in aqueous solution. Nitrazepam, however, was found to decompose with monophasic kinetics consistent with initial amide hydrolysis. Reactions involving the hydrolysis of the azomethine bond were shown to be independent of acid concentration and subject to inhibition by micelles of sds. Reactions involving amide hydrolysis were shown to be first order in acid concentration and subject to micellar catalysis. The mechanistic change for the hydrolysis of nitrazepam on transfer from water (initial azomethine cleavage) to micelles of sds (initial amide cleavage), was presumably the result of the inhibition of azomethine hydrolysis and the catalysis of amide hydrolysis by the micelles.

Thiohydantoins. XI Kinetic Studies of the Alkaline Hydrolysis of 1-Acyl-2-thiohydantoins

1972 ◽  
Vol 50 (23) ◽  
pp. 3780-3788 ◽  
Author(s):  
Wayne I. Congdon ◽  
John T. Edward
Keyword(s):  
Carboxylic Acid ◽  
Alkaline Solution ◽  
Alkaline Hydrolysis ◽  
Ground State ◽  
Kinetic Studies ◽  
Steric Effects ◽  
Hydroxide Ion ◽  
Entropy Of Activation ◽  
Hydrolysis Of ◽  
Conjugate Base

1-Acyl-2-thiohydantoins ionize in alkaline solution (pK ∼ 7). In solutions more alkaline than pH > 11 they are rapidly hydrolyzed to 2-thiohydantoin and a carboxylic acid, by attack of a hydroxide ion on the conjugate base of the 1-acyl-2-thiohydantoin. Possible mechanisms to accord with the entropy of activation, which is less negative than usual for base-catalyzed amide hydrolyses, are discussed. 1-Benzoyl-2-thiohydantoin hydrolyzes more rapidly than 1-acetyl-2-thiohydantoin, possibly because the ground state of the former molecule is destabilized by steric effects.

Kinetic studies of xylan hydrolysis of corn stover in a dilute acid cycle spray flow-through reactor

2010 ◽  
Vol 5 (2) ◽  
pp. 252-257 ◽  
Author(s):  
Hongman Zhang ◽  
Qiang Jin ◽  
Rui Xu ◽  
Lishi Yan ◽  
Zengxiang Lin
Keyword(s):  
Corn Stover ◽  
Kinetic Studies ◽  
Dilute Acid ◽  
Acid Cycle ◽  
Xylan Hydrolysis ◽  
Flow Through ◽  
Hydrolysis Of

scholarly journals Remodeler Catalyzed Nucleosome Repositioning: Influence of Structure and Stability

2020 ◽  
Vol 22 (1) ◽  
pp. 76
Author(s):  
Aaron Morgan ◽  
Sarah LeGresley ◽  
Christopher Fischer
Keyword(s):  
Free Energy ◽  
Dna Replication ◽  
Recent Work ◽  
Chromatin Remodeling ◽  
Chromatin Structure ◽  
Genetic Information ◽  
Molecular Machines ◽  
Mechanical Work ◽  
Eukaryotic Genome ◽  
Hydrolysis Of

The packaging of the eukaryotic genome into chromatin regulates the storage of genetic information, including the access of the cell’s DNA metabolism machinery. Indeed, since the processes of DNA replication, translation, and repair require access to the underlying DNA, several mechanisms, both active and passive, have evolved by which chromatin structure can be regulated and modified. One mechanism relies upon the function of chromatin remodeling enzymes which couple the free energy obtained from the binding and hydrolysis of ATP to the mechanical work of repositioning and rearranging nucleosomes. Here, we review recent work on the nucleosome mobilization activity of this essential family of molecular machines.

Dilute Acid Hydrolysis of Wheat Straw Oligosaccharides

2008 ◽  
Vol 153 (1-3) ◽  
pp. 116-126 ◽  
Author(s):  
Luís C. Duarte ◽  
Talita Silva-Fernandes ◽  
Florbela Carvalheiro ◽  
Francisco M. Gírio
Keyword(s):  
Acid Hydrolysis ◽  
Wheat Straw ◽  
Dilute Acid ◽  
Dilute Acid Hydrolysis ◽  
Hydrolysis Of

Micellar catalysis of organic reactions. VIII. Kinetic studies of the hydrolysis of 2-acetyloxybenzoic acid (aspirin) in the presence of micelles

1982 ◽  
Vol 35 (7) ◽  
pp. 1357 ◽  
Author(s):  
TJ Broxton
Keyword(s):  
Aqueous Solution ◽  
Cetyltrimethylammonium Bromide ◽  
Cetylpyridinium Chloride ◽  
Kinetic Studies ◽  
Base Catalysis ◽  
Plateau Region ◽  
General Base ◽  
Mechanism Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of 2-acetyloxybenzoic acid in the pH range 6-12 has been studied in the presence of micelles of cetyltrimethylammonium bromide (ctab) and cetylpyridinium chloride (cpc). In the plateau region (pH 6-8) the hydrolysis is inhibited by the presence of micelles, while in the region where the normal BAC2 hydrolysis (pH > 9) occurs the reaction is catalysed by micelles of ctab and cpc. The mechanism of hydrolysis in the plateau region is shown to involve general base catalysis by the adjacent ionized carboxy group both in the presence and absence of micelles. This reaction is inhibited in the presence of micelles because the substrate molecules are solubilized into the micelle and water is less available in this environment than in normal aqueous solution.

The determination of urea in soil extracts and related samples—a review

Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 709 ◽  
Author(s):  
David F. Lambert ◽  
John E. Sherwood ◽  
Paul S. Francis
Keyword(s):  
Enzymatic Hydrolysis ◽  
Flow Injection Analysis ◽  
Acidic Solution ◽  
Clinical Applications ◽  
Urease Inhibitors ◽  
Viable Option ◽  
Soil Extracts ◽  
Diacetyl Monoxime ◽  
Hydrolysis Of

Although the dominant methods for the determination of urea in clinical applications incorporate selective enzymatic hydrolysis of urea, the determination of urea in soil extracts is complicated by the presence of urease inhibitors. The spectrophotometric determination of urea with an acidic solution diacetyl monoxime and semicarbazide is a viable option but traditional manual procedures are time-consuming. New variations on these procedures, based on microplates or flow-injection analysis methodologies, allow a far greater number of samples to be analysed with high precision and sensitivity.

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