Process for the preparation of trifluoromethylphenols

Claim 1

A process for the preparation of a trifluoromethylphenol or the corresponding alkoxy compound which comprises contacting a halogenobenzotrifluoride of the formula ##STR10## in which X denotes halogen, R 1 , R 2 and R 3 denote hydrogen, trifluoromethyl or a substituent which promotes the replacement of X by a hydroxyl group and Y denotes hydrogen, halogen or alkoxy, at least one of the substituents R 1 , R 2 and R 3 representing a trifluoromethyl group and at least one of them representing a substituent which promotes the replacement of the radical X by a hydroxl group, with an excess aqueous alkali metal hydroxide in an alcoholic solution in the presence of a quaternary onium salt of the formula ##STR11## in which Z denotes an atom of main group 5 of the periodic system, R 4 to R 7 independently of one another denote alkyl , substituted alkyl, cycloalkyl, substituted cycloalkyl, aryl, or substituted aryl, of two of the radicals R 4 to R 7 , together with the central atom Z which can additionally contain additional hetero-atoms, form a heterocyclic ring, the radicals R 4 to R 7 together containing at least 6 carbon atoms, and A denotes a chloride, bromide or hydroxide anion, at a temperature of from 0° to 80° C.