1: 1-iodo-3,5-bis(trifluoromethyl)-benzene With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: formic acid ethyl ester in tetrahydrofuran; hexane T=-78°C; 3 h; 3: With ethanol; iodine; potassium carbonate in tetrahydrofuran; hexane T=-78 - 20°C; 16 h;