The electroreduction of 4-and 5-substituted benzofurazans was investigated at a platinum electrode in acetonitrile. Standard potentials for the reactions were linearly related to the energy of the lowest vacant molecular orbital as estimated by Hiickel theory. Standard rate constants for electron transfer decreased as standard potentials in the series became more cathodic. This decrease is attributed to a double layer effect. No correlation was obtained between standard rate constants and observed hyperfine splitting constants for the anion radicals.L'electrortduction des benzofurannes substituts en -4 et -5 a &ti. ttudite dans I'aci.tonitrile au moyen d'une tlectrode en platine. Les potentiels standard pour les rkactions ont &ti. relies d'une faqon lintaire aux orbitales moleculaires vacantes les plus basses telles qu'estimtes par la thtorie d'Hiickel. Les constantes de vitesse standard pour le transfert d'~1ectrons dkcroissent au fur et a mesure que les potentiels standard dans les series deviennent plus cathodiques. Cette diminution est attribuke A un effet de double couche. Aucune corrtlation n'a ete obtenue entre les constantes de vitesse standard et les constantes hyperfines de dtdoublement observtes pour les radicaux anioniques.
Several alkyl N-(o-nitrophenyl)carbamates have been shown to undergo thermal breakdown to give benzofurazan with the methyl derivative giving the optimum results.
A new synthesis of nitriles is reported based on the pyrolysis of oxime carbonates.
!On rapporte une nouvelle synthese des nitriles qui fait appel A la pyrolyse de carbonates d'oximes.
The use of high resolution flow nmr has made possible the detection and characterization by nmr of the transient intermediate σ-complex on the actual substitution pathway in the nucleophilic aromatic substitution reaction of 1-ethoxy-2,4-dinitronaphthalene (3) with n-butylamine, and the assignment of its uv-visible spectrum. The intermediate is unambiguously identified as the σ-complex (4) and the reaction is one where the two-step mechanism is clearly applicable.
A new procedure for the synthesis of substituted benzo-2,1,3-oxadiazoles (benzofurazans) has been established. The method involved the pyrolysis of substituted methyl N-(0-nitropheny1)carbamates. A possible mechanism for the reaction is outlined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.