PROCESS FOR THE PREPARATION OF ORTHO-TRIFLUOROMETHYL ANILINE

摘要

A process for preparing orthotrifluoromethyl aniline from trifluoromethyl benzene is disclosed. The steps are (a) reacting the trifluoromethyl benzene with gaseous chlorine in the presence of a chlorination catalyst until at least 90% of the trifluoromethyl benzene is consumed; (b) nitrating the crude mixture from step (a) using a mixture of sulfuric acid and nitric acid until disappearance of the chlorotrifluoromethyl benzenes; (c) settling and washing the organic phase from step (b); (d) subjecting the organic phase from step (c) to a first hydrogenation under pressure in the presence of a hydrogenation catalyst consisting of Raney nickel and/or Raney nickel doped with chromium, in an organic-solvent medium until complete disappearance of the chloronitrotrifluoromethyl benzenes; (e) subjecting the mixture from step (d) to a second hydrogenation in the presence of an additional amount of Raney nickel and in the presence of at least one alkaline base; and (f) removing the orthotrifluoromethyl aniline by distillation from the reaction mixture.