Anti-inflammatory 1-substituted 2-imidazolidinones

The synthesis and anti-inflammatory activity of a series of 1-substituted 2-imidazolidinones are reported. These compounds exerted marked anti-inflammatory activity in the carrageenan-induced hindpaw edema assay in the rat in doses that failed to elicit side effects. Their ED50 values were near the value of aspirin but markedly higher than the value of indomethacin.