NUCLEOPHILIC AROMATIC-SUBSTITUTION REACTIONS OF UNACTIVATED ARYL HALIDES WITH THIOLATE IONS IN HEXAMETHYLPHOSPHORAMIDE

A simple, high-yields method for the synthesis of aryl thioethers via nucleophilic displacement of unactivated aryl halides by the sodium salts of thiols in hexamethylphosphoramide (HMPA) is reported. The reactions are proceeding by the bimolecular displacement mechanism SNAr. Competitive experiments showed that the four halogenobenzenes presented comparable reactivities toward isopropanethiol anions; the relative halogen mobility was 1 > F > Br > CI. The effect of some substituents on the reactivity of chlorobenzene has also been measured. © 1979, American Chemical Society. All rights reserved.