A new approach was proposed for the synthesis of 5-chloro-, 5-bromo-, and 5-iodo-6-aminouracils in high yields by halogenation of 6-aminouracil with the corresponding N-halosuccinimides. For the first time, the constants and thermodynamic characteristics of the acid-base equilibrium of 6-aminouracil and its 5-halogen-substituted derivatives were determined by potentiometric titration in aqueous solutions. The effect of the nature of halogen atoms on the acid-base properties of 6-aminouracil was shown. For the first time, the solubility values in aqueous buffer systems with pH 2.0 and 7.4 at 25 and 37°C, as well as the lipophilicity values of 5-halogen-substituted 6-aminouracils, were determined by high-performance liquid chromatography.
Akhiyarov et al. (Thu,) studied this question.