Synthesis and Radioiodinelabeling of β-Amyloid Plaques Imaging Agent 3’-¹³¹I-PIB

The synthesis and biodistribution of β-amyloid plaques imaging agent 2-(3’-iodo-4’-methylaminophenyl)-6-hydroxy-benzothialzole（3’-¹³¹I-PIB）were reported. The chemical structure of the labeling precursor 2-(3’-tributylstannyl-4’-methylaminophenyl)-6-hydroxybenzothialzole and all its intermediates were verified by ¹H NMR and MS. The radioiodinated compound was prepared using iododestannylation reaction by hydrogen peroxide. Final radiochemical purity is above 95% determined by TLC. The in vivo biodistribution of 3’-¹³¹I-PIB in normal mice shows excellent brain uptake and washout, indicating this benzothiazole (BTA) derivative has potential for in vivo imaging amyloid deposits. 