% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@INPROCEEDINGS{Willmann:865229,
      author       = {Willmann, Michael and Ermert, Johannes and Neumaier, Bernd},
      title        = {{N}ovel 18{F}-labeled {D}4-receptor ligands},
      reportid     = {FZJ-2019-04760},
      year         = {2019},
      abstract     = {The role of the dopamine D4-receptor subtype in the
                      development of neurodegenerative diseases such as
                      schizophrenia has been discussed for several decades.
                      Specific radiotracers for more detailed preclinical and
                      clinical investigations are still missing so far. The
                      objective of this study was to develop D4-selective
                      radioligands for positron emission tomography (PET). The
                      selected lead structures exhibit high D4R subtype
                      selectivity and a suitable LogP values, rendering them
                      attractive for the development of a D4-selective radioligand
                      for PET-imaging. Two D4R-ligands, know from literature, were
                      selected for labeling with fluorine-18 (t1/2=108 min), the
                      most ideal positron emitting nuclide.D4R-radioligand [18F]I
                      was synthesized from 2-[18F]fluorophenylpiperazine 2,
                      obtained by an alcohol enhanced Cu(II)-mediated
                      radiofluorination of the Boc-protected precursor 1 followed
                      by deprotection of the radiolabeled intermediate with TFA.
                      Subsequently, [18F]I was obtained by reductive amination
                      with 3 in a total isolated radiochemical yield of 7 $\%$
                      within 2 h. Three independent auto radiographic studies with
                      molar activities up to 90 GBq/µmol showed high content of
                      non-specific binding that covers any possible specific
                      binding. The chiral D4R-radioligand [18F]II was also
                      obtained by alcohol enhanced Cu(II)-mediated
                      radiofluorination of the boronic acid precursor 4 in a RCY
                      of 66±5 $\%$ within 60 min after isolation by
                      semi-preparative HPLC. Preliminary in vitro autoradiographic
                      study indicates specific binding of [18F]II in areas with
                      D4-expression, consistent with results published earlier.},
      month         = {Sep},
      date          = {2019-09-01},
      organization  = {DPhG Annual Meeting 2019, Heidelberg
                       (Germany), 1 Sep 2019 - 3 Sep 2019},
      subtyp        = {After Call},
      cin          = {INM-5},
      cid          = {I:(DE-Juel1)INM-5-20090406},
      pnm          = {573 - Neuroimaging (POF3-573)},
      pid          = {G:(DE-HGF)POF3-573},
      typ          = {PUB:(DE-HGF)24},
      url          = {https://juser.fz-juelich.de/record/865229},
}