**5. Patents**

The nitro- or bromo- precursor for the radiosynthesis of the structurally modified analogs of FACH is subject of a patent application by Helmholtz-Zentrum Dresden-Rossendorf (DMPA registration No. 10 2019 112 040.3) with following contributing inventors: Rare¸s-Petru Moldovan, Masoud Sadeghzadeh, Barbara Wenzel, Mathias Kranz, Steffen Fischer, Rodrigo Teodoro, Friedrich-Alexander Ludwig, Magali Toussaint and Peter Brust.

**Supplementary Materials:** The following are available online. Figure S1: (**A**) Representative semi-preparative radioand UV-HPLC chromatograms representing two peaks a/b which are supposed to reflect neutral and deprotonated form of the radiotracer ([18F]**1a**/**b**) (conditions: Reprosil-Pur 120 CN, 10 <sup>μ</sup>m, 250 <sup>×</sup> 20 mm, 45% MeOH/20 mM NH4OAc (aq.), 7.0 mL/min); (**B**) Analytical radio- and UV-HPLC chromatograms detected two peaks a/b which assumed to be the neutral and deprotonated form of the final product ([18F]**1a**/**b**) in the sample solution co-eluted with the non-radioactive reference 1 (conditions: Reprosil-Pur C18-AQ, 250 × 4.6 mm, gradient with an eluent mixture of ACN/20 mM NH4OAc (aq.), 1.0 mL/min)., Figure S2: Analytical UV- and radio-HPLC chromatograms representing two peaks a/b which are supposed to reflect the neutral and deprotonated form of the radiotracer ([18F]**1a**/**b**) in the mouse brain sample at 30 min p.i. measured under reversed-phase conditions (Reprosil-Pur C18-AQ, 250 × 4.6 mm, gradient with an eluent mixture of ACN/20 mM NH4OAc (aq.), 370 nm, 1.0 mL/min).

**Author Contributions:** Conceptualization, M.S., B.W., W.D.-C., R.-P.M., L.R.D. and P.B.; Data curation, D.G., M.T., F.-A.L., and G.S.; Formal analysis, D.G., W.D.-C., F.L., S.J., and S.K.J.; Funding acquisition, M.S., L.R.D., and P.B.; Investigation, M.S., B.W., D.G., W.D.-C., M.T., S.J., S.K.J., G.S., and V.R.M.; Methodology, M.S., B.W., S.F., R.T., G.S., and V.R.M.; Project administration, M.S. and P.B.; Resources, W.D.-C., R.T., S.F., and V.R.M.; Software, D.G. and G.S.; Supervision, L.R.D. and P.B.; Validation, B.W., D.G., W.D.-C, R.-P.M., F.-A.L., R.T., S.K.J., V.R.M., L.R.D., and P.B.; Visualization, M.S.; Writing—original draft, M.S., B.W., G.S., and D.G.; Writing—review & editing, M.S., B.W., D.G., W.D.-C., M.T., R.-P.M., S.F., F.-A.L., R.T., S.J., S.K.J., G.S., V.R.M., L.R.D., and P.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** Masoud Sadeghzadeh was kindly financially supported by the Alexander von Humboldt Foundation and L. R. Drewes was supported by the University of Minnesota Foundation. This research received no further external funding.

**Acknowledgments:** The Alexander von Humboldt Foundation and the University of Minnesota Duluth are acknowledged for financial supports. We are thankful to K. Franke and A. Mansel for providing [18F]fluoride as well as Matthias Scheunemann and Susann Schröder for their scientific supports. We also thank the staff of the Institute of Analytical Chemistry, Department of Chemistry and Mineralogy of the University of Leipzig, for recording and processing the NMR and HR-MS spectra.

**Conflicts of Interest:** The authors declare no conflict of interest. The Humboldt Foundation had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
