Synthesis, radiosynthesis and in vivo evaluation in mice of [123I]-(4-fluorophenyl) {1-[2-(4-iodophenyl)ethyl]piperidin-4-yl}methanone for visualization of the 5-HT2A receptor with SPECT.

This work reports the synthesis, radiolabelling and preliminary in vivo evaluation of [(123)I]-(4-fluorophenyl){1-[2-(4-iodophenyl)ethyl]piperidin-4-yl}methanone. The tributylstannylprecursor was synthesized with a yield of 30%. Radiolabelling was performed using an electrophilic iododestannylation. Tracer yield was 80%, radiochemical purity was >95% and specific activity was at least 55 Ci/micromol. Log P was 1.5. The tracer showed uptake in mice brain (2.72% ID/g tissue at 5 min p.i.) and therefore will be evaluated further by regional brain biodistribution and displacement studies in rabbits.