Abstract: A compound represented by the following formula or a salt thereof: wherein each of A1, A2, A3 and A4 independently represents a carbon or nitrogen, R1 is a radioactive halogen substituent, R2 is a group selected from the group consisting of hydrogen, a hydroxyl group, a methoxy group, a carboxyl group, an amino group, an N-methylamino group, an N,N-dimethylamino group and a cyano group, and p is an integer of 0 to 2, provided at least one of A1, A2, A3 and A4 represents a carbon, and R1 binds to a carbon represented by A1, A2, A3 or A4, is effective as an image diagnosis probe targeting amyloid and a diagnostic agent for Alzheimer's disease.

Abstract: The present invention provides a compound which has affinity with amyloid, shows sufficiently rapid clearance from normal tissues and is suppressed in toxicity such as mutagencity. Provided is a compound represented by the following formula (1) or a salt thereof: wherein A1, A2, A3 and A4 independently represents a carbon or nitrogen; R1 is a halogen substituent; R2 is a halogen substituent; and m is an integer of 0 to 2, provided that at least one of R1 and R2 is a radioactive halogen substituent, at least one of A1, A2, A3 and A4 represents a carbon, and R1 binds to a carbon represented by A1, A2, A3 or A4 as well as a low-toxic diagnostic agent comprising a compound represented by the preceding formula or a salt thereof.

Abstract: A compound represented by the following formula or a salt thereof: wherein each of A1, A2, A3 and A4 independently represents a carbon or nitrogen; R1 is a group selected from the group consisting of hydrogen, hydroxyl group, carboxyl group, sulfuric acid group, amino group, nitro group, cyano group, non-radioactive halogen substituents, alkyl substituents with 1-4 carbon atoms and alkoxy substituents with 1-4 carbon atoms; and R2 is a radioactive halogen substituent, provided at least one of A1, A2, A3 and A4 represents a carbon, and R1 binds to a carbon represented by A1, A2, A3 or A4, is effective as an image diagnosis probe targeting amyloid and as well as a diagnostic agent for Alzheimer's disease including the compound represented by the above formula or a salt thereof.