THE LABELING OF 2-OXOQUAZEPAM WITH ELECTROPHILIC F-18

2-Oxoquazepam, 7-chloro-1-(2,2,2-trifluoroethyl)-1,3-dihydro-5-(2-fluorophenyl)-2H-1,4-benzo-diazepine-2-one, is a benzodiazepine agonist. It has been shown to bind in vitro with a higher affinity to benzodiazepine type 1 receptors than to type 2 receptors. Here we report the synthesis of a trimethyltin precursor and demonstrate the feasibility of using it for radiolabelling acid- and base-sensitive benzodiazepine structures such as 2-oxoquzepam. Conversions of the electrophilic fluorine to [F-18]-2-oxoquazepam on the order 20-25% were obtained.