Design and synthesis of novel CCR3 antagonists.

As part of our investigation into the development of potent CCR3 antagonists, a series of piperidine analogues was designed and prepared. Exploration of the piperidine core examined both the basicity and the location of a nitrogen, as well as conformational variants. The bicyclo-piperidine 24c was found to be the most potent inhibitor of CCR3 with an IC(50) of 0.0082 microM in the binding assay and 0.0024 microM in the chemotaxis assay.