RATE PRODUCT CORRELATIONS FOR CONCURRENT NUCLEOPHILIC DISPLACEMENTS OF HALOTRIAZINES BY HYDROXIDE AND ALKOXIDES IN WATER

Rates and products of reactions of a fluorotriazine dye 1 with a range of alcohols (including tetrahydropyran-2-methanol, and alpha- and bet a-methylglucopyranoside and others given below) have been investigated in dilute aqueous solution at pH 11.2 and 25 degrees C by ion pair hi gh performance liquid chromatography. The pseudo first-order rate; con stants when dissected, using product ratios, into contributions from t he competing hydrolysis and alcoholysis reactions, show that the rates of hydrolysis are usually unchanged within experimental errors by add ition of ca. 1% of the alcohols. However, hydrolysis rate constants ar e enhanced by addition of alpha- and beta-methylglucopyranoside. Secon d-order constants, calculated from pK(a) data (for propan-1-ol, methan ol, ethane-1,2-diol, sorbitol, mannitol) for attack by alkoxide, decre ase in the order of alcohols listed. Similar data for monosubstitution s of a dichlorotriazine dye 2 show that both rate constants and produc t ratios are strongly temperature dependent; the medium effect of addi tives (e.g. urea, salts) was also examined. A non-linear dependence of rate constant with alcohol concentration was observed for reaction of 2 with glucose, and several products were formed. The results illustr ate the importance of mass law effects on the rates of these reactions .