Fully automated synthesis and purification of 4-(2'-methoxyphenyl)-1-[2'-(N-2?-pyridinyl)-p-[18F]fluorobenzamido]ethylpiperazine

We have developed an efficient synthesis method for the rapid and high-yield automated synthesis of 4-(2'-methoxyphenyl)-1-[2'-(N-2-pyridinyl)-p-[18F]fluorobenzamido]ethylpiperazine (p-[18F]MPPF). No-carrier-added [18F]F- was trapped on a small QMA cartridge and eluted with 70% MeCN(aq) (0.4mL) containing Kryptofix 222 (2.3mg) and K2CO3 (0.7mg). The nucleophilic [18F]fluorination was performed with 3mg of the nitro-precursor in DMSO (0.4mL) at 190 degrees C for 20min, followed by the preparative HPLC purification (column: COSMOSIL Cholester, Nacalai Tesque, Kyoto, Japan; mobile phase: MeCN/25mm AcONH4/AcOH=200/300/0.15; flow rate: 6.0mL/min) to afford p-[18F]MPPF (retention time=9.5min). p-[18F]MPPF was obtained automatically with a radiochemical yield of 38.6 +/- 5.0% (decay corrected, n=5), a specific activity of 214.3 +/- 21.1GBq/mu mol, and a radiochemical purity of >99% within a total synthesis time of about 55min. Copyright (C) 2012 John Wiley & Sons, Ltd.