Synthesis and Carbon Labeling of ¹¹C-PIB for Aβ-Amyloid Imaging

Assessing the deposition of Aβ-amyloid in the living brain is important for diagnosis and treatment of Alzheimer’s disease(AD). 2-(4′-N-¹¹C-methyl-aminophenyl)-6-hydroxybenzothiazole( ¹¹C-PIB) was used as a ideal labeled probe imaging Aβ-amyloid for AD. The precursor of ¹¹C-PIB, 2-(4′-aminophenyl)-6-hydroxybenzothiazole, was synthesized. ¹¹C-PIB was labeled with ¹¹C-CH₃-Triflate（Trifluoromethanesulfonate）under unprotect 6-hydroxyl precursor at room temperature. The labeling yield, radiochemistry purity and specific activity are 52.6%(corrected, n=35), 99% and 18.0TBq/mmoL respectively. The by reaction occurrs when the reaction is heated 80℃ for 2 min. The radiochemistry purity can be improved to 99% by semi-HPLC weak acid mobile phase.