2-Methylpyridinium/pyridinium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olates as potent anticonvulsant agents—synthesis and crystal structure

The molecular salt, 2-methylpyridinium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropy-rimidin-4-olate) (I), is prepared from the ethanolic solution of 1-chloro-2,4-dinitrobenzene, pyrimidine-2,4,6-(1H,3H,5H)-trione (barbituric acid) and 2-methylpyridine at room temperature, and the molecular salt, pyridinium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate (II), is prepared from the same reactants, by dissolving them in hot DMSO and ethanol mixture at 70°C. The structures of I and II are characterized by visible, IR, ¹H-NMR, ¹³C-NMR and elemental analysis and confirmed by single crystal X-ray analysis. Both the salts crystallize in triclinic crystal system with sp. gr. $P\overline{1}$. They possess noticeable anticonvulsant activity even at low concentration (25 mg/kg). Acute toxicity studies of these complexes indicate that LD₅₀ values are greater than 1500 mg/kg and the tested animals do not show any behavioural changes.