Ammonium Chloride → Dimethyl(2-i-propylindenyl)(2,7-dimethyl-4-i-propylindenyl)silane

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Reaction Steps

In a 500-ml two-necked flask were charged 3.20 g (20.2 mmol) of 2-i-propylindene, 48.6 mg (0.54 mmol) of copper cyanide, and 100 ml of diethyl ether. To the mixture was added at -78° C. 14.0 ml of 1.62 M hexane solution of n-butyllithium (22.7 mmol) and the mixture was stirred at room temperature for 4 hours. Subsequently, 6.57 g (23.6 mmol) of dimethyl(2,7-dimethyl-4-isopropylindenyl)silyl chloride was added at -78° C. and the mixture was stirred at room temperature for 12 hours. After addition of aqueous ammonium chloride solution to the reaction mixture, the organic layer was washed with saturated saline and dried over sodium sulfate. The sodium sulfate was removed by filtration and the organic solvent was distilled off under reduced pressure. The residue was purified by column chromatography (silica gel, development solvent: n-hexane:methylene chloride=9:1) to obtain 6.85 g (17.1 mmol, yield: 84.7%) of a pale yellow oil as the target. The product was confirmed to be a mixture of isomers by 1H-NMR.

Provenance & Evidence