Synthesis and characterization of Schiff bases derived from 5-aminouracil and N-heterocyclic aldehydes

Resumo

New Schiff bases of 5-aminouracil have been synthesized by the 1: 1 condensation with N-heterocyclic aldehydes. The new compounds were characterized by elemental analyses and ¹H NMR spectroscopy. Under similar conditions, the condensation of 6-aminouracil with aldehydes failed to yield the desired Schiff base. Interestingly, the reaction of 6-aminouracil with 6-methylpyridine-2-carbaldehyde resulted in an unusual compound, 2-methyl-6-[7-(6-methylpyridin-2-yl)-2,4-dioxo-1,2,3,4-tetrahydropyrimido[4,5-d]pyrimidin-5-yl]-pyridinium methanesulfonate, whose crystal structure was elucidated by X-ray crystallography.