Acid-Catalyzed Decomposition of Trialkyltriazenes: Protected Alkyldiazonium Ions

Article abstract of DOI:10.1021/ja00392a032

The ecid-catalyzed decomposition of 1,3-di-n-butyl-3-methyltriazene and the synthesis and decomposition of 1,3-bis(cyclprpopylcarbinyl)-3-methyltriazene are reported.A kinetic study of the acid-catalyzed decomposition of 1,3-di-n-butyl-3-methyltriazene indicates that the reaction is subject to general acid catalysis.The rates of reaction have been studied by monitoring the disappearance of a triazene UV absorption band (263 nm).A plot of the buffer concentration vs. k_obsd was a straight line, whose slope gave k_cat = 1.84 *10^-2 min^-1M^-1.A linear dependence of the log (k_obsd) on pH (6.9 - 8.4) was observed, along with a solvent isotope effect (k_D/k_H) of 2.05.The products of the decomposition of the butyltriazene (n-butyl and sec-butyl alcohols and 1- and 2-butene) were accounted for by the intermediacy of a diazonium ion.The mechanism was corroborated by the product analysis of the decomposition of the (cyclopropylcarbinyl)triazene.The alcoholic products isolated were cyclopropylcarbinyl alcohol (48percent), cyclobutyl alcohol (48percent) and 3-buten-1-ol (4percent).This distribution is conclusive evidence that these trialkyltriazenes decompose in aqueous media to produce alkyldiazonium ions or directly to prduce carbonium ions in cases where the alkyl group is capable of stabilizing a positive charge.