Water → 2-Bromo-3-n-octylthiophene

To a 250 mL of two-ported flask filled with 3-octylthiophene (10.00 g, 50.93 mmol) was added 60 mL of DMF. A solution of NBS (9.26 g, 52.03 mmol) in 60 mL of DMF was added dropwise in an iced saline bath. After addition was completed, the mixture was warmed to the room temperature and then stirred at this temperature overnight. The reaction was stopped and the resultant product was poured into 200 mL of water. The mixture was extracted with dichloromethane (60 mL×4). The organic phase was washed with aqueous potassium hydroxide solution (2 M, 100 mL), saturated saline (100 mL) and water (100 mL×2), successively. The organic phase was dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure. The resultant product was separated with chromatographic column, in which eluant was petroleum ether, to give a liquid as oil (12.60 g, yield: 89%).