Hydrolysis of acetamide

If ki = ki, p7/min = U2 pA" . This is an unusual condition it has been observed in the hydrolysis of acetamide at 100°C. Since pA" = 12.32 at 100°C, the minimum rate in this reaction occurs at pH 6.16. For ester hydrolyses, ki is usually greater than ki, and the minimum is observed near pH 5-6 (at room temperature). Equation (6-57) is used in the construction of a calculated pH-rate profile, when it allows... 

In a different approach a super-high-throughput ee-assay was developed on the basis of chirally modified capillary array electrophoresis (CAE).90 CAE was used in the Human Genome Project, and commercially available instruments have been developed which comprise a high number of capillaries in parallel, for example the 96-capillary unit MegaBACE consisting of 6 bundles of 16 capillaries.91 The system can address a 96-well microtiter plate. It was adapted to perform ee-determinations of chiral amines, which are potentially accessible by catalytic reductive amination of ketones, transition metal catalyzed Markovnikov addition of ammonia, or enzymatic hydrolysis of acetamides (Scheme 14).90... 

Amidase (bacteria) HA at 10-30 mM is an activator of amidase-induced hydrolysis of acetamide (enhancing fccat) 52, 53... 

The foregoing process is based on the method of W. A. Noyes and W. F. Goebel,9 in which equimolecular proportions of ammonium acetate and acetic acid are heated together, the acetic acid having been shown to accelerate both the dehydration of ammonium acetate and the hydrolysis of acetamide. 

Benrath184 used a dilatometric method to follow the acid-catalysed hydrolysis of acetamide, whereas Leisten212 and Rabinovitch and Winkler187 both analysed for the liberated ammonia by the formol method281. 

A key step in the hydrolysis of acetamide in aqueous acid proceeds by nucleophilic addition of... 

Hydrolysis not expected to be significant based on estimated half-lives for hydrolysis of acetamide of 261, 3950, and 46 yr at pH 5,7,9, respectively, which were calculated using experimental acid and base hydrolysis rate constants for acetamide (Mabey Mill 1978 selected, Howard et al. 1991). 

Properties of Acetamide (SECTION 221).—(a) Hydrolysis of acetamide.—Mix about 0.5 gram of acetamide with about 5 cc. of a solution of sodium hydroxide, shake and observe whether the odor of ammonia is present. Heat the solution to boiling. Is ammonia set free (Eq.)... 

The other example is the hydrolysis of acetamide in solutions of strong acids, where it has been found that kR/kR = 1.50 in 0.1 IV acid, 1.00 in 2.3 N acid, and 0.86 in 4.0 N acid (Reitz, 111,112). This accords excellently with the conclusions reached in Sec. III.3.a, according to... 

The hydrolysis of acetamide, acetonitrile and benzonitrile was also investigated at higher temperatures (350-450 °C, 28-32 MPa) in a tubular reactor [17] without addition of catalysts. The measured activation energy of acetonitrile decreases with pressure, which was assumed to be a consequence of catalysis by H30 ions. At higher pressure the self-dissociation of water increases, leading to an increased concentration of OH and H3O+ ions. 

Is the acid-catalyzed hydrolysis of acetamide a reversible or an irreversible reaction Explain. 

The pi e-equilibrium proton transfer is demonstrated by the HjO-DjO solvent effect on the rate of hydrolysis of acetamide in dilute acid (Reitz, 1939), and the slow bimolecular attack of water is demonstrated by the effect of substituents on the rate in dilute acid (see Ingold, 1953, p. 784 for review Leisten, 1959). Hydrolyzing benzamide does not exchange its oxygen with the solvent (Bender and Ginger, 1955 Bender et al., 1954). This observation gives no indication as to whether the attacking water molecule adds or substitutes, but only shows that if it adds then the decomposition of the adduct is fast and does not influence the measured rate. 

The volume of activation for the hydrolysis of acetamide in dilute acid is —9-4 i 0-5 cm mole (Osborn et al., 1961) which is almost identical with that for the acid-catalyzed and base-catalyzed hydrolysis of methyl and ethyl acetates and for the other simple bimolecular ion-molecule reactions listed in Tables 2 and 6. It seems likely, therefore. 

Chitosan is prepared by hydrolysis of acetamide groups of chitin. This is normally conducted by severe repetitions of alkaline hydrolysis due to treatment due to the resistance of such groups imposed by the trans arrangement of the C2-C3 substituents in the sugar ring [57]. Thermal treatments of chitin under strong aqueous... 

PROBLEM 10.33 Using eq. 10.42 as a model, write an equation for the hydrolysis of acetamide. 

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