Structure-Activity Studies on Benzhydrol-Containing Nipecotic Acid and Guvacine Derivatives as Potent, Orally-Active Inhibitors of GABA Uptake

Article abstract of DOI:10.1021/jm00100a032

The introduction of lipophilic groups onto the ring nitrogen of nipecotic acid and guvacine, two known GABA uptake inhibitors, afforded potent, orally-active anticonvulsant drugs.A series of compounds is reported which explores the structure-activity relationships (SAR) in this series.Among the areas explored: side-chain SAR (aromatic-, heterocyclic-, and tricyclic-containing side chains) and modifications to the tetrahydropyridine ring.The benzhydrol ether-containing side chains afforded the most potent compounds with several exhibiting in vitro IC50 values for GABA uptake of <1 μM (including 5, Table I; 37, 43, Table IV; and 44, Table V).Compound 44 was selected for extensive evaluation and subsequently progressed to Phase 1 clinical trials with severe adverse effects seen after single dose administration to humans.