1: 95 percent / Br2, azodiisobutyronitrile / CCl4 / 1.) reflux, 4 h; 2,) room temp., 48 h 2: 80 percent / triethylamine / benzene / 24 h / Ambient temperature 3: 41 percent / benzene / 24 h / Ambient temperature View Scheme

1: 80 percent / triethylamine / benzene / 24 h / Ambient temperature 2: 41 percent / benzene / 24 h / Ambient temperature View Scheme

in benzene 24 h; Ambient temperature;

in benzene 24 h; Ambient temperature;

triethylamine in dimethyl sulfoxide T=75°C; 4 h;

1: triethylamine / dimethylsulfoxide / 4 h / 75 °C 2: 34 percent / triethylamine / dimethylsulfoxide / 4 h / 75 °C View Scheme