Synthesis and Carbon Labeling of ~(11)C-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.