124617-86-3Relevant articles and documents
Evidence for the Formation of Nitrenium Ions in the Acid-catalysed Solvolysis of Mutagenic N-Acetoxy-N-Alkoxybenzamides
Campbell, John J.,Glover, Stephen A.,Hammond, Gerard P.,Rowbottom, Colleen A.
, p. 2067 - 2080 (2007/10/02)
In aqueous acetonitrile, N-acetoxy-N-alkoxybenzamides undergo acid-catalysed solvolysis by the AAl1 mechanism to give acetic acid and nitrenium ions.This is indicated by an inverse dependence of the acid-independent rate constant, kH, upon the activity of water, a solvent kinetic isotope effect of 0.44 and positive Σ(excit.) values.In addition, relief of steric compression at the nitrogen enhances the rate of solvolysis.Hammett correlations with ?+ substituent constants were found for the rates of solvolysis of para-substituted-N-acetoxy-N-butoxybenzamides and N-acetoxy-N-(para-substituted benzyloxy) benzamides.This fact and the low ρ-values of -1.35 and -1.56, respectively, are indicative of a strong build-up of positive charge in the transition state which has both nitrenium ion and oxonium ion character and is in accordance with computed molecular-orbital properties of N-alkoxynitrenium ions.Greater levels of mutagenicity have been measured for those compounds which are more readily solvolysed to nitrenium ions.
