Rates and equilibrium constants for the covalent hydration of 5-bromo-2(1H)-pyrimidinone in aqueous solution

Article abstract of DOI:10.1139/v86-209

The kinetics of bromination of the title compound (1) have been measured in aqueous solutions of pH 0-6.The change in the order of reaction which occurs around pH 2.5 is explained by 1 reacting via its covalent hydrate, 3.Furthermore, there is sufficient 3 present at equilibrium that the kinetics of its equilibration with 1 were also measured.From these two studies the extent of covalent hydration of 1 is estimated to be 5percent.Kinetic studies of the bromination of the dimethyl cation 5 and of its equilibration with the pseudobase 6 were also carried out for the purposes of comparison.The present results for 1, 3, 5 and 6 are compared to earlier results for 2-pyrimidinone and analogous derivatives.