FK-584

N-tert-Butyl-4,4-diphenyl-2-cyclopentenylamine ((+/-)-3) was designed to restrict the conformation of terodiline 1 and was synthesized in a 6-step approach starting with diphenylacetaldehyde (10) or in a 4-step approach starting with 2,2-diphenyl-4-pentenoic acid (17). Using di-p-toluoyltartaric acid as a resolving agent, the synthetic (+/-)-3 was resolved into its optically pure forms, (-)- and (+)-3. The (-)-enantiomer (-)-3.HCl (FK584) showed about ten times more potent inhibitory activity on urinary bladder rhythmic contraction in rats (ED30 = 0.18 mg/kg, i.v.) than terodiline (ED30 = 1.9 mg/kg, i.v.), while the (+)-enantiomer (+)-3.HCl showed no inhibitory activity at 1.0 mg/kg i.v. Compound (-)-3.HCl (FK584) has pharmacological properties similar to those of terodiline, as evaluated by in vitro assay and is currently in clinical development for the treatment of overactive detrusor.

We synthesized the racemates of the five presumed metabolites (1b-f) of (S)-(--)-N-tert-butyl-4,4-diphenyl-2-cyclopentenylamine hydrochloride (FK584, S(--)-1a), a novel agent for the treatment of overactive detrusor syndrome, in order to confirm the structures of the metabolites and also to evaluate their inhibitory activity against detrusor contraction. (+/-)-N-tert-Butyl-4-(4-hydroxyphenyl)- and 4-(4-hydroxyphenyl)- and 4-phenyl-2-cyclopentenylamines (1b--e) were synthesized via 5-(4-methoxyphenyl)- and 5-(4-benzyloxy-3-methoxyphenyl)-5-phenyl-2-cyclopenten-1-one (9g, h), respectively. Compounds 1b-f prepared in this study were identical with the metabolites in human urine in gas chromatography-mass spectrometry and analytical HPLC. The inhibitory activity of compounds 1b-f against detrusor contraction in vitro induced by electrical field stimulation in guinea-pigs was less potent than that of FK584.