Abstract: The present invention relates to a compound represented by the following General Formula (1) or a salt thereof. In General Formula (1), R1, R2, R3 and R4 each independently represent a hydrogen atom, a linear or branched alkyl group which may have a substituent or the like. R1 and R2 may be bonded to each other to form a ring. R3 and R4 may be bonded to each other to form a ring. R1 and/or R2 may be bonded to a 6-membered ring to which —NR1R2 is bonded to form a ring. R3 and/or R4 may be bonded to a 6-membered ring to which —NR3R4 is bonded to form a ring. R5 represents —11CH3, a linear or branched alkyl group which may have a substituent or the like. R6 represents —F, —18F or the like. X, Y and Z each independently represent a carbon atom, an oxygen atom or the like. n is 0 or 1.