REMOTE-CONTROLLED ONE-STEP PRODUCTION OF F-18 LABELED BUTYROPHENONE NEUROLEPTICS EXEMPLIFIED BY THE SYNTHESIS OF NCA [F-18] N-METHYLSPIPERONE

A remote controlled synthesis for the routine production of [F-18]butyrophenones is described. The modular set-up includes a one step HPLC- and a solid phase extraction unit both connected on-line to a single unit reactor. [F-18]N-methylspiperone was synthesized from 8-[4-(4-nitrophenyl)-4-oxobutyl]-3-methyl-1-phenyl-1,3,8-triazaspiro [4,5]decan-4-one using the direct nucleophilic aromatic fluorination in presence of a cryptate consisting of Kryptofix(R) 2.2.2, potassium oxalate and a small amount of potassium carbonate (50 mu g). The one-step synthesis gave radiochemical yields of 15-20% within a synthesis time of 70 min, including product formation. Starting with the appropriate amount of F-18-fluoride up to 180 mCi [F-18]MSP have been obtained. The radiochemical purity is in the range of 96-98% and the specific activity is > 4000 Ci/mmol. The system is generally useful for the synthesis of other n.c.a. [F-18]butyrophenone neuroleptics such as [F-18]N-methylbenperidol starting with the corresponding nitro precursors.