Synthesis of the metabolites of 4-(2-methyl-1H-imidazol-1-yl)-2,2-diphenylbutanamide (KRP-197/ONO-8025)

We synthesized the six presumed metabolites (2--7) of 4-(2-methyl-1H-imidazol-1-yl)-2,2-diphenylbutanamide KRP-197/ONO-8025, 1], a urinary incontinence therapeutic agent, in order to confirm the structures of the metabolites. Metabolite (2) was synthesized via glucuronidaion of compound (1) and methyl 2,3,4-tri-O-benzoyl-1-methanesulfonyl-alpha-D-glucopyranuronate. Metabolite (3) was synthesized via 3-(tert-butoxycarbonyl)-2-methyl-1,3-imidazolidine-4,5-dione. Metabolites (4--7) were synthesized via 4-amino-2-diphenylbutanamide, respectively. The structures of the metabolites (2--7) in humans were identified by means of synthesis of the authentic compounds.