Studies on the structure-activity relationship of 1,3,3,4-tetra-substituted pyrrolidine embodied CCR5 receptor antagonists. Part 1: Tuning the N-substituents.

A novel series of CCR5 antagonists has been identified, utilizing the lead, nifeviroc, which were further modified based on bioisosteric principles. Lead optimization was pursued by balancing potential toxicity and potency. Potent analogues with low toxic properties were successfully developed by formation of urea and amide bonds at the nitrogen at position 4- of the pyrrolidine ring.