2-4- 4-- 4--1- Improved Process for Preparing 2-4-trifluoromethoxyphenylethylamine and 4-bromomethyl- and 4-chloromethyl-1-trifluoromethoxybenzene

摘要

PURPOSE: An improved process for preparing 2-(4-trifluoromethoxyphenyl)ethylamine and 4-bromomethyl- and 4-chloromethyl-1-trifluoromethoxybenzene from trifluoromethoxybenzene is provided. CONSTITUTION: The process for preparing 2-(4-trifluoromethoxyphenyl)ethylamine comprises the steps of converting trifluoromethoxybenzene by halomethylation into 4-halogenomethyl-1-trifluoromethoxybenzene, converting the 4-halogenomethyl-1-trifluoromethoxybenzene by halogen-cyano exchange into (4-trifluoromethoxy)acetonitrile, and reducing the (4-trifluoromethoxy)acetonitrile using hydrogen in the presence of a nickel catalyst to form 2-(4-trifluoromethoxyphenyl)1 ethylamine, wherein the halomethylation is carried out using formaldehyde and (a) hydrogen bromide, optionally in the presence of a Lewis acid and/or a protic acid as catalyst, or (b) hydrogen bromide released from a bromide using a strong acid, or (c) sodium bromide in the presence of a Lewis acid and/or a protic acid as catalyst. The process for preparing 4-bromomethyl- or 4-chloromethyl-1-trifluoromethoxybenzene comprises converting trifluoromethoxybenzene by bromomethylation or chloromethylation into the 4-bromomethyl- or 4-chloromethyl-1-trifluoromethoxybenzene.