New 4(1H)-pyridinone derivatives as analgesic agents.

A number of 2-methyl/ethyl-3-hydroxy-4(1H)-pyridinones have been synthesized by reacting with 4-pyrones and primary aromatic amines in ethanol. Their structures were confirmed by microanalysis, IR and 1H-NMR spectral analysis. Possible analgesic and anti-inflammatory activities of the synthesized compounds were investigated by acetic acid-induced writhing and carrageenan rat paw edema tests. All compounds exhibited higher analgesic activities than acetylsalicylic acid, 1-(2-Piperidinoethyl)-2- methyl-3-hydroxy-4-(1H)-pyridinone.2HBr(1), 1-[2-(1-methyl-pyrrolidine-2- yl)-ethyl]-2- methyl-3-hydroxy-4(1H)-pyridinone.2HBr (3) and 1-[2-(1-methyl-pyrrolidine- 2-yl)-ethyl]-2- ethyl-3-hydroxy-4(1H)-pyridinone.2HBr (6) showed higher anti-inflammatory activities than indometacin.