Kinetics and mechanism of the hydrolysis of methyl pyridyl and methyl quinolyl ketoximes in sulphuric acid

Abstract

The kinetics of hydrolysis of methyl 2-, 3-, and 4-pyridyl and 2-, 5-, 6-, 7-, and 8-quinolyl ketoximes in sulphuric acid have been studied over a wide range of acidity. Comparison of the rates of the hydrolyses with those of methyl 1-methylpyridinium and 1-methylquinolinium ketoximes, and with those for acetophenone oxime, show the reactive species to be those which are protonated both on the heterocyclic nucleus and on the oximino-group. The rate-determining step is postulated to be the base-catalysed loss of hydroxylamine from the tetrahedral intermediate formed by the attack of water on the di-cation of the oxime.