Discovery of novel cyclopentane carboxylic acids as potent and selective inhibitors of Na1.7.
Sun S, Chowdhury S, Hemeon I, Hasan A, Wilson MS , et al.
Bioorganic & medicinal chemistry letters •
Discovery efforts leading to the identification of cyclopentane carboxylic acid 31, a potent inhibitor of Na1.7 that showed high selectivity over Na1.5 and exhibited robust analgesic effects in an inherited erythromelalgia (IEM) transgenic mouse assay, are described herein. Key design elements that culminated in the discovery of 31 include exploration of proline substituents, replacement of the proline warhead with cyclopentane carboxylic acid, that led to significantly boosted Na1.7 potency, and replacement of the metabolically labile adamantane motif with the 2,6-dichlorobenzyl substituted piperidine system, that addressed metabolic instability and led to a significant improvement in PK.