The MMP inhibitor (R)-2-(N-benzyl-4-(2-[18F]fluoroethoxy) phenylsulphonamido)-N-hydroxy-3-methylbutanamide: Improved precursor synthesis and fully automated radiosynthesis

The CGS 25966 derivative (R)-2-(N-Benzy1-4-(2-[F-18]fluoroethoxy)phenyl-sulphonamido)-N-hydroxy3-methylbutanamide [F-18]9 represents a very potent radiolabelled matrix metalloproteinase inhibitor. For first human PET studies it is mandatory to have a fully automated radiosynthesis and a straightforward precursor synthesis available. The realisation of both requirements is reported herein. In particular, the corresponding precursor 8 was obtained in a reliable 7 step synthesis with an overall chemical yield of 2.3%. Furthermore, the target compound [F-18]9 was prepared with a radiochemical yield of 14.8 +/- 3.9% (not corrected for decay). (C) 2011 Elsevier Ltd. All rights reserved.