64583-55-7Relevant academic research and scientific papers
Synthesis and thermal decomposition of N,N-dialkoxyamides
Digianantonio, Katherine M.,Glover, Stephen A.,Johns, Jennifer P.,Rosser, Adam A.
body text, p. 4116 - 4126 (2011/06/28)
N,N-Dialkoxyamides 1c, a virtually unstudied member of the new class of anomeric amides, amides bearing two electronegative atoms at nitrogen, have been synthesised in useful yields directly from hydroxamic esters using phenyliodine(iii)bis(trifluoroacetate) (PIFA). Infrared carbonyl stretch frequencies and carbonyl 13C NMR properties have been reported, which support strong inhibition of amide resonance in these amides. Their thermal decomposition reactions in mesitylene at 155°C proceed by homolysis to form alkoxyamidyl and alkoxyl free radicals in preference to HERON rearrangements to esters. The reactions follow first-order kinetics and for a series of N,N-dimethoxy-4-substituted benzamides, activation energies of 125-135 kJ mol-1 have been determined together with weakly negative entropies of activation.
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.
