Radiosynthesis of 2′-deoxy-2′-[18F]-fluoro-5-methyl-1-β-l-arabinofuranosyluracil ([18F]-l-FMAU) for PET

Radiosynthesis of 2′-deoxy-2′-[18F]-fluoro-5-methyl-1-β-l-arabinofuranosyluracil ([18F]-l-FMAU) is reported. Compound 1 was synthesized and converted to 2-triflate 2. Compound 3 was prepared from 2 using tetrabutylammonium[18F]fluoride, converted to 4, and then coupled with 5. The crude product was hydrolyzed, and purified by HPLC to obtain 7a. The radiochemical yield of [18F]-l-FMAU was 26% decay corrected (d.c.) in four runs with radiochemical purity >99% and specific activity 2200 mCi/μmol. The synthesis time was 3.3–3.5 h from the end of bombardment (EOB).