A mixture of ethoxybenzene (67 g), chloropentafluoroacetone (100 g) and aluminium chloride (7 g) was charged to a Hastalloy lined cell at -78° C., the cell sealed and heated to 120° C. for 8 hours. After cooling and venting, the residue was taken up in chloroform and filtered through silica gel. After removal of the solvent by evaporation the residual solid was recrystallised from n-hexane to yield several crops of 1,1,1,3,3-pentafluoro-2-(4-ethoxyphenyl)-3-chloropropan-2-ol. (Total 70 g) mp. 84°-86° C.
