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Radiochemical labelling of the dopamine D 3 receptor ligand RGH‐1756
Author(s) -
Langer Oliver,
Gulyás Balázs,
Sandell Johan,
Laszlovszky István,
Kiss Béla,
Domány György,
Ács Tibor,
Farde Lars,
Halldin Christer
Publication year - 2000
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/1099-1344(20001015)43:11<1069::aid-jlcr390>3.0.co;2-n
Subject(s) - chemistry , radioligand , piperazine , dopamine receptor d3 , ligand (biochemistry) , dopamine , dopamine receptor , desmethyl , in vivo , receptor , dopamine receptor d2 , labelling , biodistribution , stereochemistry , in vitro , metabolite , biochemistry , medicine , organic chemistry , microbiology and biotechnology , biology
The dopamine D 3 receptor is expressed in low density in limbic brain areas. The receptor subtype has been proposed as a target for novel antipsychotic drugs, however no selective positron emission tomography (PET) ligand is to date available to study the receptor distribution in vivo . 1‐(2‐Methoxyphenyl)‐4‐{4‐[4‐(6‐imidazo[2,1‐b]‐thiazolyl)phenoxy]butyl}piperazine (RGH‐1756) is a new methoxy‐phenylpiperazine derivative that possesses high affinity (K i : 0.119 nM) and good selectivity for the human dopamine D 3 receptor. In an attempt to develop a PET radioligand for the visualisation of the dopamine D 3 receptor in human brain we synthesised carbon‐11‐labelled RGH‐1756. The radiolabelling was performed by reaction of the corresponding desmethyl precursor 1‐(2‐hydroxyphenyl)‐4‐{4‐[4‐(6‐imidazo[2,1‐b]‐thiazolyl)phenoxy]butyl}piperazine (04512626) with [ 11 C]methyl tri‐flate in acetone and aqueous NaOH. The HPLC‐determined incorporation yield was >90%. The total synthesis time was 35 min and the specific radioactivity at end of synthesis ranged from 66 to 132 GBq/µmol. Copyright © 2000 John Wiley & Sons, Ltd.