1066-45-1

165190-76-1

1025451-57-3

To a tetrahydrofuran (THF, 85 mL) solution of 2,2,6,6-tetramethylpiperidine (4.22 g, 29.9 mmol) was slowly added a hexane solution of n-butyllithium (1.6 M, 18.69 mL, 29.9 mmol) at -78°C. The reaction mixture was then cooled to -78°C for 1 h. The reaction mixture was then cooled again to -78°C. After stirring at -78°C for 1 h, the reaction mixture was warmed to room temperature and subsequently cooled again to -78°C. Subsequently, a solution of 4,7-bis(thiophen-2-yl)benzo[C][1,2,5]thiadiazole (3.45 g, 11.5 mmol) in THF (35 mL) was added dropwise. Stirring was continued at -78°C for 2 h. A hexane solution of trimethyltin chloride (1.0 M, 29.9 mL, 29.9 mmol) was then added. The reaction mixture was slowly warmed to room temperature and stirred for 12 hours. Upon completion of the reaction, the reaction was quenched with deionized water and extracted with ether. The organic phase was washed several times with deionized water and subsequently dried over anhydrous magnesium sulfate (MgSO4) and concentrated to dryness under reduced pressure. The residue was recrystallized by acetone to give 4,7-bis(5-(trimethylstannyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (6.38 g, 89% yield) as orange crystals.