Ionisation constants of some substituted quinazolines and triazanaphthalenes

Abstract

As ordinarily measured, the pK_a values of many substituted quinazolines and triazanaphthalenes are composite because of reversible covalent hydration of the cations. By using a rapid-reaction apparatus, the true pK_a values of some of these compounds have been obtained and the equilibrium concentration ratios of hydrated to “anhydrous” cations have been calculated. The true pK_a values of pteridine is predicted from the present results.