N-(4-cyanophenyl)-2-[4-(1,3-dimethyl-2,4-dioxo-5H-pyrrolo[4,5-d]pyrimidin-6-yl)phenoxy]acetamide N-(4-cyanophenyl)-2-[4-(2,4-diketo-1,3-dimethyl-5H-pyrrolo[4,5-d]pyrimidin-6-yl)phenoxy]acetamide N-(4-cyanophenyl)-2-[4-(1,3-dimethyl-2,4-dioxo-5H-pyrrolo[4,5-d]pyrimidin-6-yl)phenoxy]ethanamide