Novel one-pot one-step synthesis of 2'-[(18)F]fluoroflumazenil (FFMZ) for benzodiazepine receptor imaging

Nucl Med Biol. 2003 Jul;30(5):521-7. doi: 10.1016/s0969-8051(03)00030-1.

Abstract

We describe the synthesis of 2'-[(18)F]fluoroflumazenil (FFMZ), which differs from the typically used [(18)F]fluoroethylflumazenil (FEFMZ) for benzodiazepine receptor imaging. For one-pot one-step labeling, the precursors, 2'-tosyloxyflumazenil (TFMZ) and 2'-mesyloxyflumazenil (MFMZ), were synthesized in three steps. The precursors were successfully labeled with no-carrier-added (18)F-fluoride which was activated by repeated azeotropic distillation with Kryptofix 2.2.2./potassium carbonate in MeCN. An automated system for labeling and purification of [(18)F]FFMZ was developed. Labeling efficiency and radiochemical purity of [(18)F]FFMZ after synthesis by the automated system were 68% and 98%, respectively. Specific binding of [(18)F]FFMZ to central benzodiazepine receptor of rats was demonstrated by phosphoimaging.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Animals
  • Brain / diagnostic imaging
  • Brain / metabolism*
  • Drug Stability
  • Equipment Design
  • Equipment Failure Analysis
  • Flumazenil / analogs & derivatives
  • Flumazenil / chemical synthesis*
  • Flumazenil / pharmacokinetics*
  • Isotope Labeling / instrumentation*
  • Isotope Labeling / methods*
  • Radionuclide Imaging
  • Radiopharmaceuticals / chemical synthesis
  • Radiopharmaceuticals / pharmacokinetics
  • Rats
  • Receptors, GABA-A / metabolism*

Substances

  • 2'-fluoroflumazenil
  • Radiopharmaceuticals
  • Receptors, GABA-A
  • Flumazenil