A round bottomed flask (10 mL) was charged with N-ethyl-6-fluoro-N-(4formylbenzyl)nicotinamide 1 (0.15 g, 0.52 mmol) and acetic anhydride (2 mL). The reaction was cooled to 0 °C and then BF3•Et2O (0.05 mL) was injected. The flask was stirred at room temperature for 3 hours after which the reaction was quenched with NaHCO3 (sat. aq.) (10 mL) and then extracted with ethyl acetate (25 mL). The ethyl acetate layer was rinsed with NaHCO3 (10 mL), water (10 mL), brine (10 mL) and then dried over MgSO4. The solvents were removed under reduced pressure to yield an oily residue which was purified via flash chromatography [silica gel Biotage Sfär (10 g), DCM wet-load, ethyl acetate/methylene chloride (0:100) to (20:80)] to yield were purchased from Waters (Elstree, UK) and were conditioned using EtOH (5 mL) and water (10 mL). The precursor was synthesised according to previous reports. Analytical and semipreparative RP-HPLC were performed with an Agilent 1200 HPLC system equipped with a 1200 Series Diode Array Detector and a Raytest GABI Star NaI(Tl) scintillation detector (energy window 400-700 keV). Isolated radiochemical yield (RCY) refers to the activity of the pure tracer isolated after HPLC divided by the initial activity of [ 18 F]fluoride in [ 18 O]H2O used for the labelling. RCYs are given decay corrected. Radiochemical purity refers to the proportion of the total radioactivity in the sample which is present as the desired radiotracer, as measured by radio-HPLC.