Hydroxylamine Acetohydroxamic acid

When Jencks reacted hydroxylamine with p-nitrophenyl acetate, p-nitrophenolate ion was released at a rate faster than that at which acetohydroxamic acid was formed. This burst effect is evidence for a two-step reaction. In this case the intermediate is O-acetylhydroxylamine, which subsequently reacts with hydroxylamine to form the hydroxamic acid. 

We shall now compare some properties of prototypical examples of hydroxylamines, oximes and hydroxamic acids. These will be structures 1, 2 and 3 with methyl groups at the remaining positions, i.e. dimethylhydroxylamine (6), acetoxime (7) and acetohydroxamic acid (8). 

As points of reference, we will take two well-established hydrogen-bond donor/ acceptors, H2O and NH3. Their computed gas-phase Vs,max and Vs,mm are in Table 5, along with the same data for all of the molecules that have been discussed hydroxylamine (5), dimethylhydroxylamine (6), acetoxime (7), acetohydroxamic acid (8), and the isomeric pairs of oximes examined in the last section. Finally, we included an additional hydroxamic acid, 11, to see the effects of the strongly electron-withdrawing cyano group. 

Hydroxylamine and dimethylhydroxylamine, 5 and 6, are extremely weak acids, judging from how much less are their conjugate base /s.min than that of acetohydroxamic acid, 8. Accordingly the experimental p Ta of hydroxylamine, 5.94, must refer to its behavior as a base, with pX b = 8.06. Indeed its p Ta and its nitrogen /s.min are both quite similar to those of pyridine. 

As U is the major component of a SNF see Table 1.2, its initial separation in reprocessing alleviates the mass burden of following steps and is considered preferable. The UREX process developed in the AFCI program of the United States is based on the PUREX process (30 vol % TBP in n-dodecane) and suppression of extractions of Pu and Np by reduction/complexation (175-182). Plutonium and Np are reduced by acetohydroxamic acid (AHA, CH3CONHOH) to Pu(III), Np(V), and Np(IV). U is kept in an extractable U(VI) state. Although Np(IV) is also extractable, AHA forms a complex with Np(IV) that is soluble in the aqueous phase. In the case where reoxidation of Pu(III) occurs, the Pu(IV) also transfers to the aqueous phase by forming a Pu(IV)-AHA complex. Thus, U is exclusively extracted. AHA decomposes to hydroxylamine and acetic acid (176). 

Ethyl acetic acid ether was treated with hydroxylamine and acetohydroxamic acid was obtained. 

Acetohydroxamic acid was obtained in the result of reaction of acetamide with hydroxylamine. 

N,O-Dimethyl acetohydroxamic acid Hydroxylamine hydrochloride Phosgene... 

Colorimetric Methods. Measurement of Unchanged Acetylcholine, This colorimetric technique depends on measuring the unchanged acetylcholine with hydroxylamine to produce acetohydroxamic acid which yields a purple color with excess ferric chloride after acidification. Cook 12) originally applied this method to pesticide residue analysis on paper chromatograms. 

Sulfonic acids can be converted on reaction with thionyl chloride to corresponding chlorides, which on reaction with hydroxylamine change to sulfonyl-hydroxamic acids. These acids react in an alkaline medium with acetaldehyde with the formation of acetohydroxamic acids and sulfinic acids. Both products give colors with ferric chloride the first red, the second red-orange. 

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