This invention relates to novel compounds suitable as precursors for the preparation of certain 18F labelled positron emission tomography (PET) tracers. Furthermore, the invention relates to the preparation of such precursor molecules and to the preparation of PET tracers by 18F labelling of such precursors.本發明係關於適宜作為製備某些18F標記之正子發射斷層掃描(PET)示蹤劑之前體的新穎化合物。此外,本發明係關於製備此等前體分子及藉由18F標記此等前體來製備PET示蹤劑。