bromine in dichloromethane 20 h;

1: 98.6 percent / Br2 / CH2Cl2 / 20 h / Ambient temperature 2: 1.) n-BuLi, 2.) (PhSO2)2S / 1.) THF, n-hexane, 15 min, 2.) THF, n-hexane, -78 deg C, 2 h 3: 89.9 percent / Br2 / CH2Cl2 / 20 h View Scheme

1: 1.) n-BuLi, 2.) (PhSO2)2S / 1.) THF, n-hexane, 15 min, 2.) THF, n-hexane, -78 deg C, 2 h 2: 89.9 percent / Br2 / CH2Cl2 / 20 h View Scheme

1: 1) n-BuLi, 2) S 3: 86 percent / bromine / CHCl3 / 16 h / Ambient temperature 4: 1) n-BuLi, 2) bis(benzenesulfinyl) sulfide / 1) THF, hexane, -78 deg C, 10 min, 2) a) -70 deg C, 2 h, b) to room temperature 5: 70 percent / bromine / CHCl3 / 20 h / Ambient temperature View Scheme

2: 86 percent / bromine / CHCl3 / 16 h / Ambient temperature 3: 1) n-BuLi, 2) bis(benzenesulfinyl) sulfide / 1) THF, hexane, -78 deg C, 10 min, 2) a) -70 deg C, 2 h, b) to room temperature 4: 70 percent / bromine / CHCl3 / 20 h / Ambient temperature View Scheme