A suspension containing AlCl3 (16.2 g, 0.12 mol) was prepared from thiophene (9.6 mL, 0.12 mol) and butanedioyl chloride (5.4 mL, 0.05 mol) in 100 mL of dichloromethane. A mixed solution of thiophene and succinyl chloride was slowly added dropwise to the above suspension. The reaction mixture was stirred at 40 °C for 4 hours. After completion of the reaction, the mixture was poured into a mixture consisting of 100 g of ice and 10 mL of hydrochloric acid and stirring was continued for 30 minutes. The reaction mixture was extracted with dichloromethane, and the organic layer was washed sequentially with NaHCO3 solution and distilled water, and then dried with anhydrous MgSO4. The solvent was removed by evaporation under reduced pressure and the resulting solid residue was purified by column chromatography to afford the white solid product 1,4-bis(2-thienyl)-1,4-butanedione in 76% yield. The structure of the product was determined by 1H NMR (500 MHz, CDCl3, 25 °C, TMS, δ): 7.84 (dd, J = 3.8, 1.1 Hz, 2H), 7.67 (dd, J = 5.0, 1.1 Hz, 2H), 7.17 (dd, J = 4.9, 3.8 Hz, 2H), 3.42 (s, 4H) and MALDI-TOF MS (m/z): 251.1 [M+ + H] for confirmation.
