1: 62.4 percent / N-bromosuccinimide (NBS) / CCl4 / 4 h / Ambient temperature 2: 31 percent / salcomine, O2 / dimethylformamide / 20 h / Ambient temperature 3: 97 percent / Pd(PPh3)4, 2 N aq. Na2CO3 / tetrahydrofuran / 0.17 h / 90 °C 4: 80 mg / HClO4 / CH2Cl2 / 2 h / Ambient temperature View Scheme

salcomine; oxygen in N,N-dimethyl-formamide 14 h;