Scheme 1
Raytest Synchrom R&D Evo I layout for the automated production of (S)-[18F]FETrp from precursor (S)-3. 0: aqueous solution of [18F]fluoride in [18O]H2O; 1: anion exchange Sep-Pak® QMA cartridge (46 mg); 2: solution of TBA-HCO3 (4.4 mg, 14.5 μmol) in H2O/MeCN (1 mL, 1/1, v/v); 3: anhyd. MeCN (2 mL); 4: precursor (S)-3 (2 mg) in anhyd. DMF/t-BuOH, (1 mL, 9/1, v/v); 5: 6 M aqueous HBr solution (500 µL); 6: 1.1 M NaOAc buffer solution pH 5.5 (3.5 mL); 7: Symmetryprep C18 column (300 × 7.8 mm; 7 μm; Waters); 8: H2O/MeCN/TFA (90/10/0.01, v/v/v), isocratic mode, λ = 254 nm, flow rate = 1.5 mL/min for one min and then 2.5 mL/min; 9: collection vial pre-filled with deionised H2O (20 mL); 10: pre-conditioned Oasis MCX plus short cartridge; 11: deionised H2O (10 mL); 12: 5% NH4OH/EtOH solution (3 mL); 13: final product vial for formulation with saline (30 mL) and AcOH (135 µL)