PROCEDE DE PREPARATION DE L'ACIDE 2,5-BIS (2,2,2-TRIFLUORETHOXY)-BENZOIQUE

L'invention concerne la préparation de l'acide 2,5-bis (2,2,2-trifluoréthoxy)-benzoïque. Ce procédé de préparation comprend la réaction de la 2,5-bis (2,2,2-trifluoréthoxy)-acétophénone avec un hypochlorite. L'acide ainsi obtenu sert à la synthèse par un procédé économique du 2,5-bis (2,2,2-trifluoréthoxy)-N-(2-pipéridylméthyl)benzamide, qui est un médicament antiarythmique connu. A process for preparing 1,4- bis(2,2,2-trifluoroethoxy)benzene comprises reacting paradibromobenzene or para- dihydroxybenzene with a compound of formula CF3CH2O-A wherein A is -SO2CF3 or an alkali metal. The antiarrhythmic agent 2,5-bis(2,2,2-tri- fluoroethoxy)-N-(2-piperidyl- methyl)benzamide (flecainide) may be produced by acetylating the product of a process according to the invention in the presence of a Lewis acid catalyst, then either chlorinating the acetylated product, adding a buffering base and further chlorinating to form the corresponding alpha , alpha , alpha - trifluoroacetophenone or reacting the acetylated acetophenone with hypochlorite to form the corresponding benzoic acid and reacting the acid with inorganic acid chloride to provide the corresponding acid chloride, and then reacting the product of either of the latter pair of steps with 2-aminomethyl-piperidine to form the flecainide product in one step or with two 2-aminomethyl-pyridine followed by reduction to form the flecainide product in two steps.