3593-75-7

67061-69-2

General procedure for the synthesis of 2,5-dibromodithieno[3,2-B:2',3'-D]thiophene using dithieno[3,2-B:2',3'-D]thiophene as starting material: at 0 °C, N-bromosuccinimide (5.87 g, 33 mmol) was slowly added to dithieno[3,2-B:2',3'-D]thiophene (Aldrich, 2.94 g, 2.94 g, 2.94 g, 1.5 mmol) dissolved in an anhydrous DMF (60 mL). 15 mmol) was dissolved in a solution of anhydrous DMF (60 mL). The reaction mixture was gradually warmed to room temperature and stirred overnight. Subsequently, the reaction solution was poured into water and the precipitate precipitated was collected. The precipitate was washed with methanol and recrystallized in a chloroform/methanol solvent mixture to finally obtain off-white crystals of 2,5-dibromodithieno[3,2-B:2',3'-D]thiophene (yield: 5.14 g, 97%).1H NMR (500 MHz, CDCl3): δ 7.28 (s, 2H).