492-97-7

2,2'-BITHIOPHENE can be obtained by first preparing a Grignard reagent from 2-bromothiophene, and then coupling it with 2-bromothiophene.

At room temperature, Mg (3.5 g, 0.147 mol) was added to a three-necked flask, a condenser was added, and the reaction apparatus was sealed. The gas was evacuated (Ar gas) 3-5 times. 60 mL of anhydrous diethyl ether was injected into the three-necked flask with a syringe and stirred. Then, compound 4 (20 g, 0.123 mol) and 0.5 mL of 1,2-dibromoethane were added to an empty single-necked flask and dissolved with 30 mL of anhydrous diethyl ether. The reaction flask was then heated with a hair dryer. The dissolved mixture was added dropwise to the reaction flask with a syringe. After the addition was complete, the reaction apparatus was placed at 50 °C for 3 h. Another clean three-necked flask was taken, and compound 4 (16.7 g, 0.1 mol) and Ni(dppp)Cl2 were added to it. A condenser was added, and the reaction apparatus was sealed. The above reaction solution was then transferred to this three-necked flask with a syringe and heated to 50 °C overnight. The reaction solution was extracted with ethyl acetate, and the combined ethyl acetate phases were washed with distilled water and then dried with anhydrous sodium sulfate.