1: 6-bromo-1H-indole With potassium hydride in tetrahydrofuran; mineral oil T=0°C; 0.5 h; 2: With tert.-butyl lithium in tetrahydrofuran; mineral oil T=-78°C; 0.5 h; Inert atmosphere; 3: dimethyl-disulfide in tetrahydrofuran; mineral oil T=-78°C; 1 h;

1: 6-bromo-1H-indole With potassium hydride in tetrahydrofuran T=0°C; 0.25 h; 2: With tert.-butyl lithium in tetrahydrofuran; pentane T=-78°C; 0.25 h; 3: dimethylsulfide in tetrahydrofuran; pentane T=-78 - 20°C;