Discovery and evolution of phenoxypiperidine hydroxyamide dual CCR3/H1 antagonists. Part II: Optimising in vivo clearance

The second part of this communication focuses on the resolution of issues surrounding the series of hydroxyamide phenoxypiperidine CCR3/H1 dual antagonists described in Part I. This involved further structural exploration directed at reducing metabolism and leading to the identification of compound 60 with a greatly improved in vivo pharmacokinetic profile.