Synthesis and antiinflammatory properties of N-substituted 4,5-dioxopyrrolidine-3-carboxanilides

The synthesis and physical properties of a series of N-methyl- and N-phenyl-4,5-dioxopyrrolidine-3-carboxanilides are described. Unlike previously reported carboxanilides derived from 1,3(2H,4H)-dioxoisoquinoline and 2-oxobenzofuran, the currently described agents exist solely as the enol tautomers and, as a result, do not display comparable acidic properties. None of the newly reported compounds exhibited activity equal to that of aspirin in the carrageenin-induced rat foot edema assay.