An improved synthesis of 3′‐DEOXY‐3′‐[¹⁸F]fluorothymidine ([¹⁸F]FLT) and the fate of the precursor, 2, 3′‐anhydro‐5′‐<i>O</i>‐(4, 4′‐dimethoxytrityl)‐thymidine

Abstract

Abstract Summary The fate of the precursor, 2, 3′‐anhydro‐5′‐ O ‐(4, 4′‐dimethoxytrityl)‐thymidine was investigated during the synthesis of [ 18 F]FLT with the aim of improving the radiochemical yield. This precursor was shown to undergo a rapid base catalysed elimination reaction and to be consumed within 5–10 min. The by‐product was identified. Modification of the synthesis has produced between 1.85–3.70 GBq (50–100 mCi) of [ 18 F]FLT in 60 min using an automated synthesis system.