Process for reacting alcohols and/or phenols with phosphorus pentasulfide

In the process for reacting an alcohol and/or phenol with phosphorus pentasulfide in the presence of a catalyst, the improvement which comprises using, as the catalyst, compounds selected from the group consisting of:

• (a) phosphonium salts of the general formula ##STR12## or (b) ammonium salts of the general formula ##STR13## or (c) phosphine oxides of the general formula ##STR14## or (d) phosphine sulfides of the general formula ##STR15## or (e) phosphinic acid derivatives of the general formula ##STR16## in which formulae I through V the substituents R.sub.1, R.sub.2, R.sub.3, and R.sub.4 each stand for identical or different alkyl-, aryl-, alkaryl- or aralkyl-groups having from 1 to 22 carbon atoms, A stands for an acid radical of a hydrohalic acid, sulfuric acid, nitric acid, acetic acid or dialkyldithiophosphoric acid and X and Y, respectively, stand for both oxygen and sulfur, and M stands for a monovalent metal or hydrogen;
• and using the said compounds in a proportion of 0.001 to 5 weight %, based on the alcohol or phenol.