Theoretical studies on the acid hydrolysis of acetamide

Lee, Ikchoon; Kim, Chang Kon; Seo, Hein Su

doi:10.1016/s0040-4020(01)82101-3

Cited by 6 publications

(3 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A great deal of research has focused on revealing the mechanism of the hydrolysis of acetamide. − Hydrolysis of acetamide is widely accepted to be dominated by a nucleophilic attack by a water molecule on the carbonyl oxygen and the formation of O-protonated tautometer . However, little is known regarding the mechanism for the homogeneous gas phase pyrolysis.…”

Section: Introductionmentioning

confidence: 99%

“…13À15 Hydrolysis of acetamide is widely accepted to be dominated by a nucleophilic attack by a water molecule on the carbonyl oxygen and the formation of O-protonated tautometer. 14 However, little is known regarding the mechanism for the homogeneous gas phase pyrolysis. Generally, the pyrolysis of N-alkylated amides is thought to proceed in a way analogous to the pyrolysis of esters.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Theoretical Investigation into Competing Unimolecular Reactions Encountered in the Pyrolysis of Acetamide

et al. 2011

View full text Add to dashboard Cite

Motivated by the necessity to understand the pyrolysis of alkylated amines, unimolecular decomposition of acetamide is investigated herein as a model compound. Standard heats of formation, entropies, and heat capacities, are calculated for all products and transition structures using several accurate theoretical levels. The potential energy surface is mapped out for all possible channels encountered in the pyrolysis of acetamide. The formation of acetamedic acid and 1-aminoethenol and their subsequent decomposition pathways are found to afford the two most energetically favored pathways. However, RRKM analysis shows that the fate of acetamedic acid and 1-aminoethenol at all temperatures and pressures is to reisomerize to the parent acetamide. 1-Aminoethenol, in particular, is predicted to be a long-lived species enabling its participation in bimolecular reactions that lead to the formation of the major experimental products. Results presented herein reflect the importance of bimolecular reactions involving acetamide and 1-aminoethenol in building a robust model for the pyrolysis of N-alkylated amides.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Theoretical Investigation into Competing Unimolecular Reactions Encountered in the Pyrolysis of Acetamide

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Motivated by the need for a better understanding of the pyrolysis of N ‐alkylated amides in aqueous media, numerous studies had focused on investigating the hydrolysis of acetamide as a model compound . It is generally accepted that the hydrolysis of acetamide is initiated by the formation of O‐protonated tautometer via the nucleophilic attack of a water molecule on the carbonyl oxygen .…”

Section: Introductionmentioning

confidence: 99%

A theoretical study on the bimolecular reactions encountered in the pyrolysis of acetamide

Altarawneh

2011

J of Physical Organic Chem

View full text Add to dashboard Cite

Bimolecular reactions of acetamide with acetamide itself, acetimidic acid and acetic acid are investigated to account for the formation of the three major experimental products from the pyrolysis of acetamide, namely ammonia, acetic acid and acetonitrile. This mechanism involves bimolecular deammonation reactions to form acetamide anhydride, acetic anhydride and N-acetyl acetamide, and the subsequent fragmentation of these intermediates into acetic acid and acetonitrile. It is found that the overall reaction barrier for the formation of the three major experimental products from the bimolecular reaction of acetamide with its enol form (acetimidic acid) amount to a 36.1 kcal/mol barrier. This barrier is in excellent agreement with the corresponding experimental data from the self-condensation of acetamide. This finding stresses on the role of acetimidic acid as a major intermediate in the pyrolysis of acetamide. The calculated activation barriers for the two available pathways in the bimolecular reaction of acetamide and acetic acid into imide and N-acetyl acetamide (36.3 kcal/mol and 24.0 kcal/mol) is in accord with the corresponding experimental activation energy of 30.1 kcal/mol for the autocatalytic reaction of acetamide with the acetic acid. Reaction rate constants are obtained for all plausible reactions. Kinetic data presented herein should be instrumental in building a robust model for the decomposition of N-alkylated amides, that is, a major structural entity in biomass.

show abstract

Theoretical studies on the acid hydrolysis of methyl carbamate

1987

View full text Add to dashboard Cite

The mechanism of the A2 acid hydrolysis of methyl carbamate was investigated using MNDO method. The reaction was found to proceed in two steps: (1) the rate-determining nucleophilic attack of water on the carbonyl carbon of the N-protonated tautomer involving the tetrahedral TS; and (2) the fast subsequent proton abstraction by the leaving group, NH3, to form products. The mechanism is similar to that involved in the A2 hydrolysis of acetamide. Effects of substituents, R', R2, and R3 in R'OCONR2R3, on rates can be predicted by the changes in electron densities on alkoxy oxygen and N, in complete agreement with the experimental results. We concluded that there is no need for invoking two different mechanisms for amides and carbarnates since a common mechanism can easily accommodate all the experimental results.

show abstract

Theoretical studies on the acid hydrolysis of acetamide

Cited by 6 publications

References 18 publications

Theoretical Investigation into Competing Unimolecular Reactions Encountered in the Pyrolysis of Acetamide

Theoretical Investigation into Competing Unimolecular Reactions Encountered in the Pyrolysis of Acetamide

A theoretical study on the bimolecular reactions encountered in the pyrolysis of acetamide

Theoretical studies on the acid hydrolysis of methyl carbamate

Contact Info

Product

Resources

About