| abstract |
(Aza)indolizine derivatives represented by Formula (I) having xanthine oxidase inhibitory activities and useful as agents for the prevention or treatment of a disease associated with abnormality of serum uric acid level, prodrugs thereof, salts thereof or the like. In Formula (I), 0 to 2 of X 1 , X 2 , X 3 and X 4 are a nitrogen atom and the others are CR 1 ; one of T 1 and T 2 represents cyano and the other represents a group represented by Formula (A), with the proviso that when T 1 is cyano, at least one of X 1 to X 4 is a nitrogen atom; R 1 independently represents a hydrogen atom, a halogen atom, a hydroxy group, C 1-6 alkyl, C 1-6 alkoxy or the like; ring U represents a benzene ring or the like; m represents integral number from 0 to 2; R 2 independently represents a fluorine atom, a hydroxy group or the like. |