Synthesis and antioxidant evaluation of 4-(furan-2-yl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate esters

Biginelli-type pyrimidines contain an interesting moiety which has attracted considerable attention of medicinal chemists in the last few decades. Despite the very diverse pharmacologic effects ascribed to this kind of pyrimidines, there are few reports on the antioxidant evaluation of Biginelli pyrimidines. In this study synthesis of some novel Biginelli-type pyrimidines is reported. The prepared compounds are ester derivatives of 6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate with a simple hetaryl group, furan, at C-4 position of the pyrimidine ring. These compounds were evaluated for free radical and H2O2 scavenging activities. The reducing power of these compounds was also determined. Compound 3c was the most potent one in diphenyl picrylhydrazine scavenging activity assay with the IC50 of 0.6 mg/ml. The results of reducing power assays proved that 3d and 3e are moderate reducing agents. All of the studied compounds were very weak in scavenging hydrogen peroxide compared with gallic acid.