Synthesis of quinolinyl substitued barbituric and thiobarbituric acid derivatives

Heterocyclic compounds and their derivatives, which are developing quite rapidly andbecoming more important day by day, constitute a branch of organic chemistry.Heterocyclic compounds containing atoms of the elements such as nitrogen, sulfur andoxygen as ring members are commonly used in various fields of industry as analyticalreagents, ligands, dyestuffs, pharmaceutical substances and bioindicators.According to the literature surveys made, this research is aimed for the synthesis of somenew pyrimidinetrione derivatives containing various quinolinyl groups as substituent, andthus, they may be potentially useful.The study consists of three steps. In the first step, heteroaromatic carboxaldehydes to beused in the reactions have been prepared by the oxidation of 4-methylquinoline, 2-methylquinoline, 2,6-dimethylquinoline and 2,4,6-trimethylquinoline with seleniumdioxide, which is a mild oxidant, in the medium of dioxane.In the second step which is the main goal of this research, via Knoevenagel condensationreaction, each of these aldehydes were subjected to one-pot reaction with1,3-dimethylbarbituric acid or 1,3-diethyl-2-thiobarbituric acid and thus some newpyrimidintrione or 2-thioxopyrimidinedione compounds have been synthesized.In the last step, the structures of the all synthesized compounds have been identified byusing ultraviolet, infrared, proton nuclear magnetic resonance, 13C nuclear magneticresonance and mass spectroscopical data.Keywords: Methylquinoline, Pyrimidine, 1,3-Dimethylbarbituric acid, 1,3-Diethyl-2-thiobarbituric acid, Knoevenagel Condensation.