Zum Mechanismus der Hydrazinbildung aus Harnstoffen

Ohme, R.; Preuschhof, Helmut

doi:10.1002/prac.19703120221

Cited by 16 publications

(2 citation statements)

References 14 publications

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“…Substitution and isotope labelling studies have provided evidence for two reaction pathways for the hypohalite Scheme 2 degradation of urea, the Hofmann rearrangement and a nitrogen analogue of the Favorskii reaction (166). Both are initiated by N-halogenation and proceed through the intramolecular formation of hydrazine (Scheme 2).…”

Section: Ureamentioning

confidence: 99%

Hypohalites and related oxidants as chemiluminescence reagents: a review

et al. 2004

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This review concerns the use of hypochlorite, hypobromite and related oxidants (such as N-bromosuccinimide and 1,3-dibromo-5,5-dimethylhydantoin) as chemiluminescence reagents and includes references to 249 papers that were published prior to mid-2003. Particular emphasis has been placed on proposed emitting species and the mechanisms of the light-producing pathways. The analytical applications of this chemistry have been summarized in three tables: (1) quantification of hypohalites and related compounds (including halides, which are initially oxidized); (2) enhancement or inhibition of luminol chemiluminescence; and (3) direct chemiluminescence reactions with hypohalite reagents.

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Section: Ureamentioning

confidence: 99%

Hypohalites and related oxidants as chemiluminescence reagents: a review

et al. 2004

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“…The urea method, which includes three steps: the first one is the preparation of 1-piperidylurea (reaction 4) followed by chlorination leading to 1-piperidyl-3-chlorourea (reaction 5). The latter is finally converted to N-aminopiperidine by addition of a concentrated solution of sodium hydroxide [13][14][15]. The reaction mechanism is a Hoffmann rearrangement and the yield obtained is about 82%.…”

Section: )mentioning

confidence: 99%

Kinetics of the oxidation of N-aminopiperidine with chloramine

Darwich

Elkhatib²,

Steinhäuser³

et al. 2009

Kinet Catal

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The kinetics of the oxidation of N-aminopiperidine with chloramine was studied at different temperatures, with variable concentrations of the two reactants and at a pH ranging between 12 and 13.5. The reaction showed to be involving two steps: the first corresponded to the formation of a diazene intermediate, the second to the evolution of this intermediate into numerous compounds within a complex reactional chain. The rate law of the first step was determined by the Ostwald method and 2 found to be first order with respect to each reactant. The rate constant was determined at pH = 12.89 and T = 25°C: k 2 = 1.15 × 10 5 exp(-39/RT) M -1 s -1 (E 2 in kJ mol -1 )With decreasing pH value, the first step exhibited acid catalysis phenomena, and diazene was converted into azopiperidine particularly faster. This created overlapping UV-absorptions between chloramine and azopiperidine, also observed in HPLC. GC/MS analyses were used to identify some of the numerous by-products formed. Their proportions are dependent of both pH and the reactants' concentrations ratio. A reaction mechanism taking this relationship into account, was suggested.

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Preparative procedures

and

Stowell

1975

PATAI'S Chemistry of Functional Groups

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Zum Mechanismus der Hydrazinbildung aus Harnstoffen

Cited by 16 publications

References 14 publications

Hypohalites and related oxidants as chemiluminescence reagents: a review

Hypohalites and related oxidants as chemiluminescence reagents: a review

Kinetics of the oxidation of N-aminopiperidine with chloramine

Preparative procedures

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