Selective displacement of aryl fluorides with hydroquinone: synthesis of 4-phenoxyphenols

The selective displacement of a variety of aryl fluorides with hydroquinone has been achieved to give substituted 4-phenoxyphenols 3. In some cases the addition of 18-crown-6 resulted in a significant rate enhancement, and the reactions could be carried out at lower temperature. One of these derivatives, 3a (X = Cl) was converted to 2-propyl-4-(4-chlorophenoxy)phenol 2a, a precursor to the PPARγ receptor agonist 1.