II. SAR studies of pyridyl-piperazinyl-piperidine derivatives as CXCR3 chemokine antagonists.

Abstract The structure–human CXCR3 binding affinity relationship of a series of pyridyl–piperazinyl-piperidine derivatives was explored. The optimization campaign highlighted the pronounced effect of 2′-piperazine substitution on CXCR3 receptor affinity. Analog 18j , harboring a 2′( S )-ethylpiperazine moiety, exhibited a human CXCR3 IC 50 of 0.2 nM.