1: 1-chloro-4-ethynylbenzene With n-butyllithium in tetrahydrofuran; hexane T=0°C; 0.25 h; 2: N,O-dimethylacetohydroxamic acid in tetrahydrofuran; hexane T=-78 - 20°C; 2.5 h; Further stages.;

Iron (III) nitrate nonahydrate; 2,2,6,6-tetramethyl-piperidine-N-oxyl; oxygen; sodium chloride in toluene T=20°C; 9.5 h;

1: 1-chloro-4-ethynylbenzene With n-butyllithium in tetrahydrofuran T=-78 - 20°C; 2: With boron trifluoride diethyl etherate in tetrahydrofuran T=-78°C; 0.0833333 h; 3: acetic anhydride in tetrahydrofuran T=-78 - 20°C;