Synthesis of geminal difluorides by oxidative desulfurization-difluorination of alkyl aryl thioethers with halonium electrophiles in the presence of fluorinating reagents and its application for 18F-radiolabeling

J Org Chem. 2010 Sep 17;75(18):6086-95. doi: 10.1021/jo100689v.

Abstract

Various ω-substituted 1,1-difluoroalkanes are synthesized in good yields from alkyl aryl thioethers by a new oxidative desulfurization-difluorination protocol with the reagents combination of 1,3-dibromo-5,5-dimethylhydantoin (DBH) as an oxidizer and pyridine·9HF (Py·9HF) as a fluoride source. The reaction proceeds via a fluoro-Pummerer-type rearrangement followed by an oxidative desulfurization-fluorination step. Starting from α-fluorinated thioethers, this reaction is promising for (18)F-labeling (τ(1/2) = 110 min) of ligands applicable for positron emission tomography (PET). Using the combination of DBH and carrier-added Py·9H[(18)F]F, an (18)F-labeled difluoride was synthesized from the corresponding α-fluoro thioether with a radiochemical yield of 9%.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fluorine Radioisotopes / chemistry*
  • Halogenation
  • Hydrocarbons, Fluorinated / chemical synthesis*
  • Hydrocarbons, Fluorinated / chemistry
  • Hydrofluoric Acid / chemistry*
  • Molecular Structure
  • Oxidation-Reduction
  • Pyridines / chemistry*
  • Stereoisomerism
  • Sulfides / chemistry*

Substances

  • Fluorine Radioisotopes
  • Hydrocarbons, Fluorinated
  • Pyridines
  • Sulfides
  • pyridine
  • Hydrofluoric Acid