Total synthesis and evaluation of [18F]MHMZ

Radiochemical labeling of MDL 105725 using the secondary labeling precursor 2-[18F]fluoroethyltosylate ([18F]FETos) was carried out in yields of 90% synthesizing [18F]MHMZ in a specific activity of 50 MBq/nmol with a starting activity of 3 GBq. Overall radiochemical yield including [18F]FETos synthon synthesis, [18F]fluoroalkylation and preparing the injectable [18F]MHMZ solution was 42% within a synthesis time of 100 min. The novel compound showed excellent specific binding to the 5-HT2A receptor (Ki = 9.0 nM) in vitro and promising in vivo characteristics.