Preparation of o-Fluorophenols from Nonaromatic Precursors: Mechanistic Considerations for Adaptation to Fluorine-18 Radiolabeling

Org Lett. 2015 Nov 20;17(22):5540-3. doi: 10.1021/acs.orglett.5b02640. Epub 2015 Nov 4.

Abstract

The preparation of fluorine-18 labeled o-fluorophenols at high specific activity is challenging and requires use of [(18)F]fluoride ion as the radioisotope source. As a novel, alternative approach, we found that treatment of α-diazocyclohexenones with Selectfluor and Et3N·3HF followed by HF elimination and tautomerization afforded o-fluorophenols regioselectively and rapidly. To adapt this chemistry to (18)F radiolabeling, using bromine electrophiles in place of Selectfluor gave the o-fluorophenol via an α-bromo-α-fluoroketone intermediate in lower but still reasonable yields.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Combinatorial Chemistry Techniques
  • Fluorine Radioisotopes / chemistry*
  • Hydrocarbons, Fluorinated / chemical synthesis*
  • Hydrocarbons, Fluorinated / chemistry
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Phenols / chemical synthesis*
  • Phenols / chemistry

Substances

  • Fluorine Radioisotopes
  • Hydrocarbons, Fluorinated
  • Phenols
  • 2-fluorophenol