1,2-Dibromoethane → 1H-Indene, 3,3'-(1,2-ethanediyl)bis[4,7-dimethyl-

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Reaction Conditions

Reaction Steps

38.2 g (265 mmol) of 4,7-dimethylindene was dissolved in 350 ml of tetrahydrofuran and the solution was cooled to 0° C. Then 165 ml of n-butyllithium (1,6M in hexane, 264 mmol) was added dropwise over 2.5 hours. After warming to room temperature and stirring for 4 hours a purple solution of 4,7-dimethylindenyl-lithium was obtained. This solution was cooled to -70° C. and treated dropwise with 25,3 g of 1,2-dibromoethane (135 mmol) in 15 ml of tetrahydrofuran over 35 min. After warming to room temperature, a pale yellow solution was obtained, and then water was added. The organic phase was collected and dried over Na2SO4. The solvent was removed by vacuum evaporation to provide 20 g of crude product (48% yield).

Provenance & Evidence