Synthesis of new 6-hydroxypyrimidine-4(3Н)-onе derivatives

In this paper, 6-hydroxypyrimidine-4 (3Н)-one derivatives are considered as promising syntones for the creation of new biologically active substances. This is useful since the pyrimidine fragment is a structural component of nucleic acid bases (cytosine, thymine, uracil), uric and orotic acids, coenzymes (flavins and xanthins), a number of vitamins (folic acid, thiamine, pyridoxine, riboflavin). It is worth noting that the pharmaceutical market is widely represented with antitumor (methotrexate, imatinib, tegafur); antiviral (stavudine, zalcitabine, lamivudine, zidovudine, acyclovir, idoxuridine); immunostimulatory (isophone) and sedative drugs (phenobarbital, sodium ethaminal) based on compounds including the pyrimidine cycle. The purpose of the present work is to develop a method for producing new 2,3-diphenyl-5-(alkyl/ phenyl)-6-hydroxypyrimidin-4(3Н)-ones, proving their structure and individuality by NMR spectroscopy and mass spectrometry, elemental analysis and thin-layer chromatography. As a method of producing new 6-hydroxypyrimidin-4(3Н)-ones, a method of condensing N-phenyl-benzenecarboxymidamide with 2-substituted propanedioyldichlorides in the medium of an aprotic non-polar solvent – o-xylene is proposed. The desired products are isolated from the reaction mass using solvent distillation and a reprecipitation method. It was found that maximum yields are achieved with constant stirring of a suspension of N-phenylbenzenecarboxymidamide with a solution of 2-substituted propanedioyl dichloride in o-xylene and further heating of the reaction mass at 144 °C for 4 hours. The individuality of the synthesized compounds was confirmed by thin layer chromatography on Sorbfil® plates in the methanol-dichloroethane (1:9) system, and their structure was proved using modern physicochemical analysis methods: proton magnetic resonance spectroscopy, NMR С13 spectroscopy, mass spectroscopy and elemental analysis.