反应详情

温度

0 °C

38.2 g (265 mmol) of 4,7-dimethylindene were dissolved in 350 ml of tetrahydrofuran and the temperature of the solution was raised to 0° C. Thereafter, 165 ml of n-butyl-lithium (1.6M in hexane, 264 mmol) were added dropwise over 2.5 hours. After having allowed the whole to again reach room temperature and whilst stirring for 4 hours, a purple-red solution of 4,7-dimethylindenyllithium was obtained. This solution was cooled to −70° C. and treated, dropwise for 35 minutes, with 25.3 g of 1,2-dibromethane (135 mmol) in 15 ml of tetrahydrofuran. After the temperature was raised again to room temperature, a light yellow solution was obtained to which water was added. The organic phase was collected and dried on Na2SO4. The solvent was then evaporated under vacuum and 20 g of product (yield 48%) were obtained.

1. customwhole to again reach room temperature