Evidence for concerted acid hydrolysis of alkyl nitrites

Abstract

The results of studying the acid hydrolysis of methyl, ethyl, isopropyl, butyl, tert-butyl, pentyl, 2-bromoethyl, 2-chloroethyl and 2-ethoxyethyl nitrites in water show that the reaction is not, as widely accepted in the literature, catalysed by nucleophiles (Cl^–, Br^–, etc.), but is however subject to general acid catalysis. These findings, and the observed values of the solvent isotope effect, suggest that the substrate is protonated in the rate-controlling step of the reaction. Further, the relative reactivities of the various substrates investigated suggest a concerted mechanism in which the proton transfer occurs concurrently with the breaking of the O–N bond via a slightly imbalanced transition state.