A flexible reaction sequence was developed which starts with readily available anthranilic acids or isatoic anhydrides and leads regiospecifically to 1-alkyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids after reaction with 1,3-dicarbonyl compounds. The sequence is superior to earlier published methods by allowing electron-releasing and electron-withdrawing groups in any position on the aromatic ring, by allowing convenient substitution at C2, and better overall yield. A number of new and known antimicrobial agents were prepared and tested in vitro, demonstrating, among other things, that substitution of the H at C2 abolishes antibacterial activity.