Synthesis and pharmacological activity of metabolites of vasopressin V-1 receptor antagonist, OPC-21268

The metabolites of 1-[1-[4-(3-acetylaminopropoxy)benzoyl]piperid-yl]-3,4-dihydro-2(1H)-quinolinone (OPC-21268, 1), vasopressin V-1 receptor antagonist were synthesized to confirm the proposed structures and to examine their vasopressin V-1 receptor antagonistic activity. The structures of metabolites (2a - 6) were identified by means of comparison with synthetic compounds. The activity of the metabolites was found to be lower than that of 1.