33413-16-0Relevant academic research and scientific papers
Triazene Drug Metabolites. Part 9. Base Catalysed Deacylation of 3-Acyl-3-alkyl-1-aryltriazenes in Ethanol.
Iley, Jim,Ruecroft, Graham,Carvalho, Emilia,Rosa, Eduarda
, p. 1264 - 1273 (2007/10/02)
3-Acyl-3-alkyl-1-aryltriazenes undergo a base-catalysed deacylation reaction to liberate the corresponding cytotoxic 3-alkyl-1-aryltriazene.Reaction are first-order in both and .Second-order rate constants, k2, depend on the structure of both the substrate and the base.The values of k2 for the deformylation of 1-aryl-3-formyl-3-methyltriazenes by piperidine follow the Hammett relationship giving ρ +2.9; a similar correlation, ρ +1.6, is observed for the morpholine catalysed deacylation of 1-aryl-3-methyl-3-trifluoroacetyltriazenes.For 1-(4-cyanophenyl)-3-methyl-3-trifluoroacetyltriazene, a correlation between the aqueous pKa of the base and k2 is obtained, giving a Broensted β value of 0.36.The solvent deuterium isotope effect, k2EtOH/k2EtOD, for the piperidine-catalysed deacylation of 1-(3-pyridyl)-3-formyl-3-methyltriazene is 2.2, and 2,2,6,6-tetramethylpiperidine is some 2.4 times more effective than piperidine at catalysing the deformylation of this compound.Rate constants for the deacylation of 3-alkyltriazenes diminish in the order Me > Pr > Et.Rate constants also vary with the nature of the acyl group: thus CF3CO > HCO > MeCO > C8H17CO.The data are interpreted in terms of a mechanism that involves a rate-determining, general-base-catalysed attack of a solvent ethanol molecule at the carbonyl carbon atom of the group, followed by rapid collapse of the tetrahedral intermediate to form the monoalkyltriazene.
