反应详情

38.2 g (265 mmol) of 4,7-dimethylindene were dissolved in 350 ml of tetrahydrofuran, and the temperature of the solution was taken to 0° C. 165 ml of n-butyllithium (1.6 M in hexane, 264 mmol) were then added dropwise drop over 2.5 hours. After returning to room temperature and continued stirring for 4 hours, a red-purple solution of 4,7-dimethylindenyllithium was obtained. This solution was cooled to -70° C. and treated dropwise in the course of 35 minutes with 25.3 g of 1,2-dibromoethane (135 mmol) in 15 ml of tetrahydrofuran. After returning to room temperature, this gave a clear yellow solution, to which water was added. The organic phase was collected and dried over Na2SO4. The solvent was then evaporated in vacuum, 20 g of product (48% yield) being obtained.

1. customwas taken to 0° C
2. customAfter returning to room temperature