A salt from biologically active compounds pyridine-2,3-dicarboxylic (quinolinic) acid and cytosine.

Biologically active compounds are highly sought-after materials for developing novel structures applicable to industry. Cytosine and pyridine-2,3-dicarboxylic acid (quinolinic acid) are notably significant environmentally. Cytosine, a pyrimidine derivative, features a six-membered ring with a ketone and an amino group, constituting a fundamental nitrogenous base found in deoxyribonucleic acid (DNA). The present synthesis yielded a salt of dipyridine-2,3-dicarboxylic acid with cytosine, wherein a proton was transferred from a carboxyl group of quinolinic acid to a ring N atom in the cytosine molecule giving the salt 6-amino-2-oxo-2,3-dihydropyrimidin-1-ium 3-carboxypyridine-2-carboxylate, C₄H₆N₃O⁺·C₇H₄NO₄^-. A Hirshfeld surface analysis was conducted to examine the contribution of contacts within the salt. The structure of the salt was compared to other structures containing quinolinic acid in the Cambridge Structural Database (CSD).