Investigation of the reactivity of 4-pyrimidinecarboxylic, 6-hydroxy-4-pyrimidinecarboxylic and 5-hydroxyorotic acids with diazodiphenylmethane in various alcohols: Part III

Rate constants for the reaction of diazodiphenylmethane (DDM) with 4-pyrimidinecarboxylic, 6-hydroxy-4-pyrimidinecarboxylic and 5-hydroxyorotic acids were determined in twelve protic solvents at 30 ?C using the well known UV-spectrophotometric method. The second order rate contants for the examined acids were correlated using the appropriate solvent parameters by the equation log k = log k0 + af(e) + bs * + cngH were f(e) is the Kirkwood function of relative permittivity [(e-l)/(2e + 1 )], s * is the Taft polar constant for the alkyl group R in the alcohol ROH, and nyH is themumber of hydrogen atoms in the (-position in the alcohol. The results obtained for the investigated acids were compared with the corresponding results for benzoic, 2- and 3-hydroxybenzoic acids and the influence of the structure of the investigated acids on the reactivity in hydroxylic solvents is discussed. It was also possible to evaluate and distinguish the specific and non-specific solvent effects and their influence on the reaction rate.

Estimating Adsorption Equilibria of Phenolics on Synthetic Resins from the Polar and Nonpolar Properties of the Molecule

The adsorption of aromatic compounds on synthetic resins from aqueous solution was studied in order to develop a methodology by which adsorption equilibria, in a single- solute system, can be predicted from the physical-chemical properties of a compound of interest, and the adsorption isotherm of a reference compound. To develop this methodology, physical properties of 13 substituted phenols were described by linear free energy relationships (LFER) (Hammett polar constant and molar attractive constant) and were correlated with parameters in the Freundlich adsorption isotherm. The methodology was tested using data extracted from the literature and was found to be able to predict adsorption equilibria within a median percent deviation between the experimental and predicted data of 35.73%.