From hydroxylamines

Trichloromethyloxaziridine (98) transfers its NH group to primary amines under the conditions of its formation from hydroxylamine-O-sulfonic acid. Thus the slow... 

The procedure may be illustrated by the following equations relating to the preparation of hydroxyurea from hydroxylamine hydrochloride ... 

Jn light of your answer to Problem 19.56, propose a mechanism for the formation of 3,5-dimethylisoxazole from hydroxylamine and 2,4-pentanedione. 

Al-(Alkoxycarbonyl) 0-(arenesulfonyl)hydroxylamines [alkyl Af-(arenesulfonyloxy) carbamates] 3i-o can be easily obtained by sulfonylation of commercially available iV-(alkoxycarbonyl)hydroxylamines (alkyl V-hydroxy carbamates). Af-(Alkoxycarbonyl) hydroxylamines can be also prepared from hydroxylamine and alkyl chloroformate . ... 

Hydroxylamine is unstable as a free base. It is prepared from hydroxylamine hydrochloride, NH20H HC1, which is obtained by electrolytic reduction of ammonium chloride solution. The hydrochloride undergoes alkaline decomposition to hydroxylamine, which is collected by vacuum distdlation. 

Imines obtained from hydroxylamines are known as oximes, and imines obtained from primary amines are called Schiff s bases. An imine is formed in the presence of an anhydrous acid catalyst. 

Amarger, N., and Alexander, M. (1968). Nitrite formation from hydroxylamine and oximes by Pseudomonas aeruginosa. ]. Bacteriol. 95, 1651-1657. 

The same substance can also be obtained from hydroxylamine sulphate and fuming sulphuric acid, and by the hydrolysis of hydroxyl-amineisodisulphonic acid with hydrochloric acid.4... 

Figure 18-19 The ammonia oxidation system of the bacterium Nitrosomonas. Oxidation of ammonium ion (as free NH3) according to Eq. 18-17 is catalyzed hy two enzymes. The location of ammonia monooxygenase (step a) is uncertain but hydroxylamine oxidoreductase (step b) is periplas-mic. The membrane components resemble complexes I, III, and IV of the mitochondrial respiratory chain (Fig. 18-5) and are assumed to have similar proton pumps. Solid green lines trace the flow of electrons in the energy-producing reactions. This includes flow of electrons to the ammonia monoxygenase. Complexes HI and IV pump protons out but complex I catalyzes reverse electron transport for a fraction of the electrons from hydroxylamine oxidoreductase to NAD+. Modified from Blaut and Gottschalk.315...

The formation of oximes and hydroximic acids from hydroxylamine, and of, say, ethylnitrolic acid, CH3.C(N02)N0H, from dibromonitroethane, CH3.CBr2(N02), and hydroxylamine, observed by V. Meyer ... 

E. Divers and T. Haga 2 obtained no evidence of the existence of the second member of this series and it was therefore suggested that the series is better regarded as being derived from hydroxylamine by the substitution of sulphonic radicles in place of hydrogen, thus ... 

That the acid has the formula H2N202, and not HNO, is shown by its formation from hydroxylamine and nitrous acid. On mixing dilute solutions of hydroxylamine sulphate and sodium nitrate, the hydroxylamine nitrate loses water, thus HO-NH2 + 0=N—OH = H20 + HO—N=N—OH the silver salt is thrown down on addition of silver nitrate. 

While osmium is the metal of choice for the AA, there has been a recent report of the copper]I)-catalyzed intramolecular aminohydroxylation starting from hydroxylamines [27], The mechanism of this reaction is distinctively different, involving radicals as intermediates. 

Another source of the sp2 carbon at C-3 is an TV-acylimino ether (180). The second nitrogen at C-3 is obtained from hydroxylamine and dehydration gives the oxadiazole (181). 

Ion A, the conjugate base of nitramide, is tautomeric with ion B. B, upon loss of 0H, yields N20. Another preparation of nitrous oxide, from hydroxylamine and nitrous acid, is considered more fully as an exercise at the end of this chapter. 

Isoxazoles are made from hydroxylamine or by 1,3-dipolar cyclo additions... 

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