Synthesis and Evaluation of Novel 2-Oxo-1, 2-dihydro-3-quinolinecarboxamide Derivatives as Potent and Selective Serotonin 5-HT₄ Receptor Agonists

Abstract

A series of 8'-substituted N-(endo-8-azabicyclo[3.2.1]oct-3-yl)-1-isopropyl-2-oxo-1, 2-dihydro-3-quinolinecarboxamides were synthesized. The 5-HT₄ receptor agonistic activity was evaluated using the isolated guinea pig ileum preparation. Of the compounds synthesized, N-(endo-8-(3-hydroxypropyl)-8-azabicyclo[3.2.1]oct-3-yl)-1-isopropyl-2-oxo-1, 2-dihydro-3-quinolinecarboxamide (15a, TS-951) exhibited the most potent serotonin 5-HT₄ receptor agonistic activity. This compound had a high affinity for the serotonin 5-HT₄ receptor althought it had no affinities for other broad spectrum receptors. Furthermore, it remarkably enhanced gastrointestinal motility in conscious fed dogs without unfavorable effects that non-selective serotonin 5-HT₄ receptor agonist has. TS-951 may be useful in improving gastrointestinal dysfunction.