1: 2-bromo-5-n-hexylthiophene With iodine; magnesium in tetrahydrofuran Heating; 2: 3-(thiophen-2-yl)isobenzofuran-1(3H)-one in tetrahydrofuran T=20°C; 3: With Lawesson's reagent in dichloromethane T=20°C;

1.1: 62 percent / NBS / dimethylformamide / 40 h 2.1: magnesium; iodine / tetrahydrofuran / Heating 2.2: tetrahydrofuran / 20 °C 2.3: 60 percent / Lawesson's reagent / CH2Cl2 / 20 °C View Scheme

1.1: n-BuLi / -78 °C 2.1: 62 percent / NBS / dimethylformamide / 40 h 3.1: magnesium; iodine / tetrahydrofuran / Heating 3.2: tetrahydrofuran / 20 °C 3.3: 60 percent / Lawesson's reagent / CH2Cl2 / 20 °C View Scheme