Has an affinity to the [challenge]-amyloid clearance from normal tissues and, soon enough, I get a compound that has been suppressed toxicity of mutagenicity, etc.. [MEANS FOR SOLVING PROBLEMS] the following formula (1) [11] of independently carbon or nitrogen, R 1 is a halogen substituent, R 2 is a halogen substituent, m is an integer of 0 to 2, respectively (In the formula, A 4 and 2, A 3 A 1, A compound represented by one. however, and one is a radioactive halogen substituent either at least one of A 4 and 2, A 3 A 1, A is a carbon least of R 2 and R 1, R 1 is , low toxicity Alzheimers disease diagnostic agent comprising a compound or salt thereof represented by the formula and salts thereof, or.) binds to A 4, or 2, A 3 A is a carbon 1, A. [Selection] Figure Figure 1-1【課題】アミロイドへの親和性を有し、正常組織からのクリアランスが十分に早く、かつ、変異原性等の毒性がおさえられた化合物を得る。【解決手段】下記式(1)【化11】で表される化合物(式中、A1、A2、A3及びA4はそれぞれ独立に炭素又は窒素、R1はハロゲン置換基、R2はハロゲン置換基、mは0~2の整数である。ただし、R1及びR2の少なくともいずれか一方は放射性ハロゲン置換基であり、かつ、A1、A2、A3及びA4のうちの少なくとも一つは炭素であって、R1は、炭素であるA1、A2、A3又はA4に結合する。)又はその塩、並びに前記式で表される化合物又はその塩を含有してなる低毒性アルツハイマー病診断剤。【選択図】図1-1
