Patent ID: 8076367

Claim:
A propane-1,3-dione derivative represented by formula (I) or a pharmaceutically acceptable salt thereof symbols in the formula mean as follows, ring A: benzene which may be substituted, pyridine which may be substituted or thiophene ring, ring B: benzene or thiophene ring, R 1 : H or —CO-lower alkyl, R 2 : H, —O—R 5 , —N(R 6 )R 7 , —N 3 , —S(O) m -lower alkyl, —S(O) m —N(R 6 )R 7 halogen, pyridyl or imidazolyl which may be substituted, R 5 : H, lower alkyl, —CO-lower alkyl which may be substituted, or —CO—O-lower alkyl which may be substituted, R 6 and R 7 : may be the same or different from each other and each is H, lower alkyl, or —CO-lower alkyl, m: 0, 1 or 2, R 3 : H or lower alkyl, R 401 and R 402 : may be the same or different from each other and each is H, halogen, OH, —O-lower alkyl, or lower alkyl, X: bond, lower alkylene which may be substituted, or cycloalkanediyl, R 101 , R 102 , R 103 and R 104 : may be the same or different from one another and each is H, halogen, OH, or —O-lower alkyl which may be substituted with aryl or heteroaryl, wherein R 1 , its adjacent oxygen, R 2 , its adjacent X, and the carbon atom bonding to ring B may together form dioxolane which may be substituted.