Synthesis of a selective sigma receptor radioligand for SPECT: [123I]-1-(2-Hydroxyethyl)-4-(4-iodophenoxymethyl)piperidine

Article abstract of DOI:10.1002/(SICI)1099-1344(199607)38:7<595::AID-JLCR882>3.0.CO;2-A

[¹²³I]-1-(2-Hydroxyethyl)-4-(4-iodophenoxymethyl)piperidine has been prepared as a novel sigma receptor radioligand for tumour imaging by SPECT. This ligand was found to be selective in vitro for the sigma-1 receptor (Ki = 2.3 nM) when tested in a variety of neuroreceptor binding assays. The lipophilicity of this ligand is appropriate for crossing the blood/brain barrier (log P_7.5 = 4.0). Radioiodination was accomplished by no-carrier- added iododestannylation using chloramine-T in acetic acid. The specific activity of the radiotracer >10,000 mCi/μmole. The radiochemical yield was 63-77% EOS and the radiochemical purity was >99%.