To obtain: a compound effective as a diagnostic imaging probe that targets amyloid and an Alzheimers diagnostic agent that incorporates the compound therein. [Solution] A compound represented by formula (1) (In the formula, R1 represents a radioactive halogen substituent, and while 0-2 of A1, A2, A3 and A4 represent N, the remainder represent CH.) or a salt thereof, and an Alzheimers diagnostic agent obtained by incorporating the compound represented by formula (1) or a salt thereof. This compound and this Alzheimers diagnostic agent enter the brain following administration, and exhibit favorable clustering properties toward amyloid deposited in the brain.得到以澱粉樣蛋白為標靶作為影像診斷探索劑的化合物,以及調配該化合物之阿茲海默氏症診斷劑。下列化學式(1):所表示之化合物《化學式中,R1係放射性鹵素取代基;A1、A2、A3及A4之中的0~2個是N、其餘是CH》或其鹽類,以及調配前述化學式(1)所表示之化合物或其鹽類所作成之阿茲海默氏症診斷劑。本化合物及本阿茲海默氏症診斷劑顯示:投與後在腦內滲移,對沉積腦內的澱粉樣蛋白有良好的集合性(aggregation)。
