SYNTHESIS, ELECTRONIC STRUCTURE, AND ABSORPTION SPECTRA OF 9-HYDROXYPYRIDOPYRIMIDINIUM DERIVATIVES

Article abstract of DOI:10.1007/BF00486808

Pyrido<1,2-a>pyrimidinium salt derivatives have been prepared by condensation of 2-aminopyridinium salts with β-dicarbonyl compounds.The acid-base equilibrium dissociation constants for 2,4-dimethyl-9-hydroxypyrido<1,2-a>pyrimidinium perchlorate have been measured, and the spectroscopic characteristics of its neutral, anionic, and cationic forms have been determined; the electronic absorption spectra of the neutral and anionic forms of 2,4-dimethyl-9-hydroxypyrido<1,2-a>pyrimidinium perchlorate have been interpreted based on this experimental and calculated data.