Selective fluorination of substituted trichloromethyl benzenes by HF in liquid phase Preparation of fluorinated building blocks

A. Piou (1) , Stephane Celerier (1) , S. Brunet (1)

1 LACCO - Laboratoire de catalyse en chimie organique

The selective fluorination by successive Cl/F exchanges of alpha alpha alpha-trichlorotoluene substituted or not by a chlorine atom was studied in the presence of HF as the fluorin long agent The influence of the presence of a catalyst or a basic solvent (such as dioxane pyridine tributylphosphate) in order to control the fluorination was also investigated In mild conditions (50 C and after 1 h of reaction) HF in excess was required in order to obtained the trifluoromethylation by Cl/F exchanges The presence of SbCl(5) in small amount activated the Cl/F exchanges and only a stoichiometric amount of HF was required whatever the chlorinated molecules Selective mono and difluorination could be obtained by using basic solvents (C) 2010 Elsevier B V All rights reserved

Domaines: Catalyse; Chimie organique; Autre

A. Piou, Stephane Celerier, S. Brunet. Selective fluorination of substituted trichloromethyl benzenes by HF in liquid phase Preparation of fluorinated building blocks. Journal of Fluorine Chemistry, 2010, 131 (11), pp.1241-1246. ⟨10.1016/j.jfluchem.2010.06.013⟩. ⟨hal-00757297⟩