Ethylamine deamination

Other than water, protein is the major constituent of meat averaging nearly 21% in heef or chicken meat, with fat varying fiom 4.6 to 11.0% in beef and fiom 2.7 to 12.6% in chickoi. The principal radiolytic reactions of aqueous solutions of aliphatic amino acids are reductive deamination and decarboxylation. Alanine yields NH3, pyruvic add, acetaldehyde, propionic acid, CO2, H2, and ethylamine (6). Sulfur-containing amino adds are espedally sensitive to ionizing radiation. Cysteine can be oxidized to cystine by the hydroxyl radical or it can react with the hydrated electron and produce... 

In conclusion, we propose a specific research program for deaminations in aqueous systems based on ideas mentioned in this section, namely to investigate (a) deamination kinetics and products of a series of simple aliphatic amines in water with sodium nitrite and perchloric acid at various acidities, (b) decompositions of diazenolates of the same amines in water and (c) decompositions of a standard type of N-nitroso amides, again of the same amines and all in the same aprotic solvent. The reaction conditions should be as similar as possible in the experiments of all three series. The series of amines should include methyl-, ethyl-, 1-methylethyl-, 1-methylpropyl-, and ( cr butyl)amine and [l- H]ethylamine, but not amines with longer aliphatic chains, as the very informative work of Southam and Whiting (1982) demonstrated clearly that, in deaminations of such amines, many mechanistically complex products are formed. In addition, micellar effects increase the complexity of reactions with such amines (see Sect. 7.3). It is obvious from the series of amines that we have proposed that this program is based on the work of Brosch and Kirmse (1991), Hovinen and Fishbein (1992), Hovinen et al. (1992), Finneman et al. (1993), and Ho and Fishbein (1994). Work with chiral 1-methylpropyl- and [l- H]ethyl-amine will provide information on the stereochemistry of these reactions. 

The first attempt to detect a bridged ethyl cation in solution was that of Roberts and Yancey in 1952. These workers showed that deamination of ethylamine-l- C in aqueous solution yields ethylene and 38% ethanol that contains 1.5% ethanol-2-Clearly the bridged ion is not an important intermediate in this reaction. It has also been shown that solvolyses of ethyl-l- C toluene-p-sulfonate in acetic acid, formic acid, and 75% dioxane-water and of specifically deuterated ethyl toluene-p-sulfonate in trifluoroacetic acid and 96 % sulfuric acid " proceed without appreciable rearrangement. It seems that bimolecular solvolysis is the predominating reaction in all these solvents. However, solvolysis of deuterium-labeled ethyl toluene-p-sulfonate in fluorosulfuric acid yields a product with 30-40 % rearrangement, " and it is possible that a bridged ion is an intermediate in this reaction. 

The nitrous acid deamination appears to be as complex as the nitrosoamide reaction, and in a common solvent it appears that similar mechanisms are followed. For example, the nitrosonaphthamide of 1-phenylethylamine in acetic acid, and the reaction of 1-phenyl-ethylamine with nitrous acid in the same solvent yield 1-phenylethyl naphthoate (Table 7) and 1-phenylethanol respectively, both with 79-81% retention of configuration. These products are the intramolecular products from the respective reactions, and thte stereochemical results suggest that they are formed by a common path. Similar results were also found in the deaminations of S-cholC stanylamine 2-phenyl-2-butylamine ° and 1,2,2-triphenylethyl amine Also pertinent, is the finding that the acetates fi-om the deamination of n-propylamine in acetic acid, by the two methods, contained similar amounts of the isomeric product, isopropyl acetate the amount of isomerization observed was far greater than in the solvolysis of n-propyl tosylate in the same solvent... 

The pyrolyses of JV-nitroso-A-acetylamines also probably generate ion pairs in the usual non-polar reaction media, e.g. />-cymene, for little rearrangement is reported Diazoalkanes, formed by elimination from diazohydroxides, are unlikely intermediates in nitrous deamination, for neither ethylamine nor isobutylamine gives labelled products when the reaction is conducted in deuterated media these observations also exclude 7r-complex intermediates -... 

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