Radiosynthesis of novel N‐¹⁸F‐labeled ¹⁸F‐FHex‐α‐l‐Glu and ¹⁸F‐FHex‐β‐Glu

Abstract

N‐18F‐labeled amino acids are important substitutes for new positron emission tomography (PET) imaging tracers complementing the deficiency of 18F‐fluorodeoxyglucose (18F‐FDG). In this work, two novel N‐6‐18F‐alkyl amino acid imaging agents, 18F‐FHex‐α‐l‐Glu and 18F‐FHex‐β‐Glu, were designed and synthesized as potential probes for PET imaging of tumors. 18F‐FHex‐α‐l‐Glu was synthesized using the precursor 6 from 18F‐F− with the yield of 16 ± 4% (n = 5, uncorrected) within about 50 minutes. The specific activity was 14.5 GBq/μmol, and the radiochemical purity was more than 95%. 18F‐FHex‐β‐Glu was synthesized using the precursor 12 based on 18F‐F− with the yield of 11 ± 3% (n = 3, uncorrected) in about 60 minutes. The specific activity was 9.1 GBq/μmol, and the radiochemical purity was more than 95%.