Hydrolysis of Anilides. III. Aminolysis and General Acid-Catalysed Alkaline Hydrolysis of Trifluoroacetanilide.

Eriksson, Sven O.; Bratt, Louise; Larsen, Inger Kristin; Levstek, I.; Eržen, V.; Blinc, R.; Paušak, S.; Ehrenberg, L.; Dumanović, J.

doi:10.3891/acta.chem.scand.21-1812

Cited by 13 publications

(9 citation statements)

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“…(2) XNR' appreciable amounts of unreactive conjugate bases at high pH include dichloroand trichloroacetamide,10 trichloroand trifluoroacetanilide,24-27,31 fluoroacetanilide,28 trimethylammonioacetanilide,29 p-nitroacetanilide,23 5,5-dialkylbarbituric acids,38-40 dihydropyrimidines,41 and dihydrouracil.42 Further, the alkaline hydrolyses of a number of amides (acetanilide,22 acyl-substituted acetanilides, [25][26][27][28][29]31,32,84,35 and chlorampheni- According to this mechanism, amide hydrolysis involves reversible, general base catalyzed formation of an anionic tetrahedral intermediate, followed by general acid-general base catalyzed elimination of ammonia or amine from the intermediate. At sufficiently high pH, some amides dissociate to unreactive conjugate bases in a parasitic side equilibrium.…”

Section: Rcmentioning

confidence: 99%

Hydrolysis of formanilides in alkaline solutions

DeWolfe¹,

Newcomb²

1971

J. Org. Chem.

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The rates of alkaline hydrolysis of several metaand para-substituted formanilides are nearly independent of the nature of the substituent. pH-reaction rate profiles and entropies of activation are consistent with a mechanism involving rate-limiting general acid-general base catalyzed elimination of arylamine from the tetrahedral adduct of hydroxide ion and the anilide. p-Nitro-and p-cyanoformanilides, which are partially dissociated to unreactive conjugate bases at high pH, are anomalously reactive toward alkaline hydrolysis. The enhanced reactivity of these compounds is attributed to their hydrolysis by a mechanism involving dissociation of a dinegatively charged tetrahedral intermediate into formate ion and arylamide ion. p-Nitroa cetanilide and Nmethyl-p-nitroformanilide are also anomalously reactive, probably for the same reason.Carbonyl-lsO isotope exchange experiments and pH-rate profiles reveal that p-nitroacetanilide hydrolyzes by two processes, one first order in hydroxide ion and the other second order in hydroxide ion. The kinetics of hydrolysis of several N-methyIformanilides suggest that these reactions are mechanistically similar to hydrolyses of the corresponding formanilides.Prior to 1950, little was known about the kinetics of carboxamide saponification; Reid2•3 had investigated the effects of aryl substituents on the rate of alkaline hydrolysis of benzamides, and Crocker4 and Calvet5 had studied the influence of acyl substituents on alkaline hydrolytic reactivity of aliphatic amides.More recently, the effects of amide structure, hydroxide ion concentration, weak acids and bases, solvent composition, temperature, and other variables on the kinetics of alkaline hydrolysis of amides have been the subjects of a number of investigations. These include studies of hydrolyses of aliphatic amides,6-6 chloroacetamides,10 aliphatic and aromatic diamides,11-16 benzamides,9'16-18 glycinamide,19 and urea.20 Kinetic studies of alkaline hydrolysis of a number of N-substituted amides have also been reported. Most of these investigations concerned acetanilides,21-23 acyl-substituted acetanilides,23-32 and N-methylanilides.24,29,33-35 Sa-(1) Submitted by R. C. N. in partial fulfillment of the requirements for the M.A. (1965) and Ph.D. (1971) degrees at the University of California at Santa Barbara.(2) E. E.

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Section: Rcmentioning

confidence: 99%

Hydrolysis of formanilides in alkaline solutions

DeWolfe¹,

Newcomb²

1971

J. Org. Chem.

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“…The formation of the tetrahedral intermediate is in most cases the rate‐determining step of the reaction. However, though the addition–elimination mechanism is believed to operate in most carboxylic derivative reactions, there are several examples where the occurrence of a dianionic intermediate is proposed to explain a parabolic dependence of rate constant upon hydroxide concentration, as it happens with activated carbonyl compounds such as acetanilides,12–27 formanilides,23, 28–30 acetamides,31, 32 lactams,23, 33–35 acylpyrroles,36 ureas,37, 38 phthalamic acids,39 phthalamides40 or beta‐sultams 41…”

Section: Introductionmentioning

confidence: 99%

Basic hydrolysis of quinolinyl N,N‐dimethylcarbamates: a two‐step mechanism

Silva

Norberto

Santos

et al. 2011

J of Physical Organic Chem

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The reactivity of 6-quinolinyl and 8-quinolinyl N,N-dimethylcarbamates was examined in several aqueous basic media. A quadratic dependence was observed for the constant rates upon hydroxide concentration for both compounds, which is a typical behaviour of a mechanism involving a base-catalysed deprotonation of the tetrahedral intermediate with the formation of a dianion at high concentrations of hydroxide ion, while at lower concentrations a specific-base catalysed addition-elimination mechanism seems to be predominant. The reactivity of 8-quinolinyl N,N-dimethylcarbamate was also studied in several amine buffers, showing specific base catalysis. The reactivity of 6-quinolinyl N,N-dimethylcarbamate was studied in H 2 O and in D 2 O and the solvent isotope effect supports the proposal of a mechanism involving a specific-base hydrolysis. All results confirm the existence of a mechanism with a rate determining step involving the substrate anion and a second mole of hydroxide ion. This mechanism was so far unknown for carbamate reactivity, being only known to occur with amides. In the present study, the hydrolysis 8-quinolinyl and 6-quinolinyl N,N-dimethylcarbamates (compounds 1 and 2, respectively) were studied in several basic media, and a similar behaviour to the one showed by activated anilides was observed, in which kinetic constants show a quadratic dependence on hydroxide concentration.(wileyonlinelibrary.com)

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“…Eriksson et al reported a kinetic study of the disappearance of I in a variety of aqueous buffered solutions.3^5 These buffers include inorganic ions such as carbonate and phosphate species3 as well as amines such as morpholine,4 imidazole,4 ethanolamine,4 hydroxylamine,5 hydrazine,5 and ammonia. 4 Although the data from the inorganic buffers support the above mechanism, different kinetic terms were obtained for the amines. The new terms include general-acid catalysis of the breakdown of intermediate III by the protonated form of the buffer and basic self-catalysis of amide formation of the buffer.…”

mentioning

confidence: 97%

Amine catalysis of the hydrolysis of trifluoroacetanilide

Huffman¹

1980

J. Org. Chem.

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Hydrolysis of Anilides. III. Aminolysis and General Acid-Catalysed Alkaline Hydrolysis of Trifluoroacetanilide.

Cited by 13 publications

References 0 publications

Hydrolysis of formanilides in alkaline solutions

Hydrolysis of formanilides in alkaline solutions

Basic hydrolysis of quinolinyl N,N‐dimethylcarbamates: a two‐step mechanism

Amine catalysis of the hydrolysis of trifluoroacetanilide

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