Synthesis of 8-[18F]fluoroguanine derivatives:: In vivo probes for imaging gene expression with positron emission tomography

A new method for the preparation of 8-[F-18]fluoroguanine derivatives based on a direct radiofluorination reaction has been developed. The radiofluorination of ganciclovir (1a) with [F-18]F-2 was carried out in absolute ethanol in the presence of tetraethylammonium hydroxide at room temperature to give 8-[F-18]fluoroganciclovir (3a) in an approximately 1% radiochemical yield. Similarly, 8-[F-18]fluoropenciclovir (3b), 8-[F-18]fluoroacyclovir (3c), and 8-[F-18]fluoroguanosine (3d) were synthesized from penciclovir (1b), acyclovir (1c), and guanosine (1d), respectively, using [F-18]F-2. The structural analyses of the final products (3a, 3b, 3c, and 3d) were carried out after F-18 decay by H-1, C-13, and F-18 nuclear magnetic resonance and high resolution mass spectroscopy. NUCL MED BIOL 27;2:157-162, 2000. (C) 2000 Elsevier Science Inc. All rights reserved.