In a continuation of our work 3 on developing greener and cleaner technologies we report herein a simple method for the Friedel–Crafts alkylation of various phenols with secondary halides using Montmorillonite K-10 clay as the Lewis acid catalyst at 200 °C in the absence of solvent as the key step. Various other methods 4 are known which use solid supports (silica, alumina, K-10) doped with various Lewis acids (AlCl 3 , FeCl 3 ) in the presence of a solvent. ...