Evaluation of potent and selective small-molecule antagonists for the CXCR2 chemokine receptor

N,N‘-Diarylureas were prepared, and the structure−activity relationship relative to the CXCR2 receptor was examined. This led to the identification of a potent and highly selective CXCR2 antagonist, which in addition was shown to be functionally active both in vitro against human neutrophils and in vivo in rabbit models of ear edema and neutropenia.