After the reaction, the solution was cooled to room temperature, and it was then extracted with dichloromethane, the two phases were separated, and the water phase was extracted twice with dichloromethane. The combined organic extracts were washed three times with water, dried over Na 2 SO 4 , evaporated, and purified with column chromatography (eluding with petroleum ether/ dichloromethane, 5/1 v/v) to give 2.88 g of BTDF at a 92% yield.