| abstract |
Disclosed is a compound having affinity for amyloid, showing fully rapid clearance from a normal tissue, and reduced in toxicities including mutagenicity. Specifically, disclosed is a compound represented by the formula (1) or a salt thereof. Also disclosed is a low-toxic diagnostic agent for Alzheimer's disease, comprising a compound represented by the formula (1) or a salt thereof. (1) wherein A1, A2, A3 and A4 independently represent a carbon or a nitrogen; R1 represents a halogen substituent; R2 represents a halogen substituent; and m represents an integer ranging from 0 to 2, provided that at least one of R1 and R2 represents a radioactive halogen substituent, at least one of A1, A2, A3 and A4 represents a carbon, and R1 binds to A1, A2, A3 or A4 which represents a carbon. |