Full automatic synthesis of [ 18 F]THK-5351 for tau protein PET imaging in Alzheimer’s disease patients: 1 year experience

[ 18 F]THK-5351, a new candidate for tau protein imaging, is based on an aryl quinoline structure. We report the full automatic synthesis using disposable cassettes under pH controlled [ 18 F]fluorination. After the trapping of 88.5 ± 21.9 GBq of [ 18 F]fluoride, it was eluted with potassium methansulfonate (KOMs) (pH 7.8)/K 222 . After drying, 3 mg of the precursor was added to 1 mL DMSO and subjected to [ 18 F]fluorination at 110 °C for 10 min. After hydrolysis, the final product was purified by HPLC. The overall radiochemical yield was 31.9 ± 11.1% ( n = 22), satisfying all quality control criteria. It was stable for up to 6 h with high radiochemical purity as 99.8 ± 0.5%.