A compound having a structure represented by the general formula (I):(wherein n is 0 or 1；R1 represents a hydrogen atom (only if n = 0), a halogen atom, a C1-C6 alkyl group, a C1-C6 haloalkyl group, an optionally substituted amino group, an optionally substituted phenyl group, a C1-C6 alkylthio group, a C1-C6 alkoxy group, a C1-C6 haloalkoxy group or a C7-C12 aralkyloxy group；R2 represents - (CH2)p-[O(CH2)q]r-X (wherein X is a halogen atom, p is an integer of 1 to 6, q is an integer of 1 to 4, and r is an integer of 0 to 4)；R3 represents a hydrogen atom, a C1-C6 alkyl group, a C7-C16 aralkyl group or a C6-C14 aryl group； andR4 represents a hydrogen atom or a C1-C6 alkyl group), ora pharmaceutically acceptable salt thereof excels FAMT in terms of the tendency to accumulate intensively in cancer, the affinity for LAT1 and the selectivity for cancer, and can be labeled using an automated synthesizer in clinical settings, and therefore is useful as a highly versatile PET imaging agent.
