Based on the established reaction conditions of Cu-mediated 18 F-fluorination (28) and our own preliminary work on the heterocyclic aromatic model compounds benzoxazoles, benzothiazoles and quinoxalines (29), we performed comparative 18 Flabeling experiments on the BPin esters 3a, 3c and 3d to obtain the 18 F-labeled ligands As expected, the benzoxazole precursor 3a yielded only a low RCY of 12%, confirming previously published results on model benzoxazoles . Fortunately, the 6-Bpin esters of thiazole 3c and quinoxaline 3d could be labeled under optimised reaction conditions with RCY of 44% and 56% using the solvent system n-butanol/DMAA (2:1)