2-Aryl- and 2-alkyl-quinolin-4-ones and their N-substituted derivs. have several important biol. functions such as the Pseudomonas quinolone signal (PQS) mol. participation in quorum sensing. Herein, we report the synthesis of its biol. precursor, 2-heptyl-4-hydroxy-quinoline (HHQ) and possible isosteres of PQS; the C-3 Cl, Br and I analogs. N-Methylation of the iodide was also feasible and the usefulness of this compd. showcased in Pd-catalyzed cross-coupling reactions, thus allowing access to a diverse set of biol. important mols. The first crystal structure of PQS is also included.