1: 2,5-dibromo-3-n-hexylthiophene With n-butyllithium; N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran; hexane T=-78°C; 1 h; 2: N,N-dimethyl-formamide in tetrahydrofuran; hexane T=-78°C; 3 h;

1: 225 mg / 1.) butyllithium, 2.) Fe(acac)3 / 1.) THF, hexane, 20 min, 2.) THF, hexane, -70 deg C, 2 h 2: 95 percent / NBS / CHCl3; acetic acid / 0.5 h / Heating 3: 1.) TMEDA, butyllithium / 1.) THF, hexane, -80 deg C, 20 min, 2.) THF, hexane, RT, 5 h View Scheme

1: 95 percent / NBS / CHCl3; acetic acid / 0.5 h / Heating 2: 1.) TMEDA, butyllithium / 1.) THF, hexane, -80 deg C, 20 min, 2.) THF, hexane, RT, 5 h View Scheme