10.1 g (34 mmol) of 2-(4-fluorophenyl)-5-methyl-1-phenylhexane-1,4-dione (Example 2) and 9.3 g (102 mmol) of aniline are heated under reflux for 24 hours in a water separator in 150 ml of toluene with the addition of 500 mg of p-toluenesulphonic acid. After cooling and diluting with ethyl acetate, the mixture is washed with 1N hydrochloric acid and then with sodium hydrogen carbonate solution, dried over magnesium sulphate and concentrated in vacuo. The residue is then chromatographed over silica gel.
