Pyrimidines, Part XXII Synthesis and Properties of 5, 6‐Dihalogenouracils

Abstract

Abstract The synthesis of various 6‐mono‐ and 5,6 dihalogeno‐uracils is described. It is shown by ultraviolet absorption spectral comparisons in aqueous solutions that the neutral species of all synthesized compounds exist in the dilactam form. The monoanions are formed by loss of a proton from N‐1. pK a values and ultraviolet absorption spectra are reported and the influence of the different halogen substituents are on these properties discussed.