A novel naphthylmethylimidazole derivative 1 and its related compounds were 
identified as 17,20-lyase inhibitors. Based on the structure-activity 
relationship around the naphthalene scaffold and the results of a docking study 
of 1a in the homology model of 17,20-lyase, the 
6,7-dihydro-5H-pyrrolo[1,2-c]imidazole derivative (+)-3c was synthesized and 
identified as a potent and highly selective 17,20-lyase inhibitor. Biological 
evaluation of (+)-3c at a dose of 1mg/kg in a male monkey model revealed marked 
reductions in both serum testosterone and dehydroepiandrosterone concentrations. 
Therefore, (+)-3c (termed orteronel [TAK-700]) was selected as a candidate for 
clinical evaluation and is currently in phase III clinical trials for the 
treatment of castration-resistant prostate cancer.