Kinetic model for acid-catalysed hydrolysis of benzohydroxamic acid

The kinetics of the hydrolysis of benzohydroxamic acid have been investigated in hydrochloric, sulphuric and perchloric acids in 10% (v/v) dimethyl sulphoxide—water at 55 °C. Activation parameters were also determined. Rate correlation by the Cox—Yates excess acidity method shows an A‐2 mechanism involving rapid pre‐equilibrium protonation of the substrate followed by rate‐limiting attack of water at the carbonyl carbon atom to form a tetrahedral intermediate which collapses, in a fast step, to the products.