Urea based CCR3 antagonists employing a tetrahydro-1,3-oxazin-2-one spacer

Conformational restriction of open chain analogs with a more polar tetrahydro-1,3-oxazin-2-one spacer led to the identification of potent urea-based CCR3 antagonists that exhibited excellent selectivity over binding to CYP2D6. The in vitro binding and eosinophil shape change data are presented. Compound 19b exhibited similar selectivity and potency to our development candidate BMS-639623. (C) 2008 Elsevier Ltd. All rights reserved.