The present invention provides a compound represented by formula (I) a pharmaceutically acceptable salt thereof or a solvate thereof. This compound is capable of specifically binding to an AMPA receptor and shows extremely high brain uptake. (In the formula each of A and Z independently represents CO SO or SO2 each of X and Y independently represents S or O each of R1 R4 independently represents a hydrogen atom an alkyl group an alkenyl group an alkynyl group or a halogen group each R5 independently represents an alkyl group an alkenyl group an alkynyl group or a halogen group and n represents an integer of 0 4.)
