Abstract: A compound of the formula (I): pharmaceutically acceptable salt or solvate thereof, wherein Y is a group of the formula: wherein Ring A is optionally substituted aryl or optionally substituted heteroaryl, X3 is COOR17 or the like Y is not optionally substituted phenyl which is substituted with the formula: —CR9R10X3 at the para position, R1 to R10 are each independently halogen, hydroxy, optionally substituted lower alkyl, optionally substituted aryl or the like, X1 is —O—, —S— or the like.

Abstract: A compound of formula (I): (wherein R1-R10 are each independently hydrogen, halogen, optionally substituted lower alkyl or the like, X1 is —O—, —S—, —NR11— (wherein R11 is hydrogen, lower alkyl or the like), —CR12R13CO—, —(CR12R13)mO—, —O(CR12R13)m- (wherein R12 and R13 are each independently hydrogen or lower alkyl and m is a integer between 1 and 3) or the like, X2 is a bond, —O—, —S—, —NR14— (wherein R14 is hydrogen, lower alkyl or the like, R14 and R6 can be taken together with the neighboring atom to form a ring) or —CR15R16— (wherein R15 and R16 are each independently hydrogen or lower alkyl, R15 and R6 or R10 can be taken together with the neighboring carbon atom to form a ring, R16 and R9 can be joined together to form a bond), X3 is COOR17, C(?NR17)NR18OR19 or the like), a pharmaceutically acceptable salt or a solvate thereof.

Abstract: The present invention provides an integrase inhibitor. The inventors have have found the following compound of formula (I) possessing an integrase inhibitory activity.