2-Methyl-7-(4'-tert-butylphenyl)indene → [6-tert-Butyl-4-(3,5-di-tert-butylphenyl)-5-methoxy-2-methyl-1H-inden-1-yl][4-(4-tert-butylphenyl)-2-methyl-1H-inden-1-yl]dimethylsilane

Participants

Reaction Steps

To a solution of 5.54 g (21.1 mmol) of 7-(4-tert-butylphenyl)-2-methyl-1H-indene in 150 ml of ether 8.50 ml (21.3 mmol) of 2.5 M nBuLi in hexanes was added in one portion at −40° C. This mixture was stirred overnight at room temperature, then cooled to −40° C., and 190 mg of CuCN was added. The resulting mixture was stirred for 1 h at −20° C., then cooled to −40° C., and a solution of 10.5 g (21.1 mmol) of [6-tert-butyl-4-(3,5-di-tert-butylphenyl)-5-methoxy-2-methyl-1H-inden-1-yl](chloro)dimethyl-silane in 150 ml of ether was added in one portion. Further on, this mixture was stirred overnight at ambient temperature, then 0.5 ml of water was added. This solution was filtered through a pad of silica gel 60 (40-63 um) which was additionally washed by 2×75 ml of dichloromethane. The combined elute was evaporated to dryness, and the residue was triturated with 70 ml of n-hexane. The obtained suspension was filtered on glass frit, the precipitate was washed with 30 ml of n-hexane and dried in vacuum to give a white powder. Additionally, the mother liquor was evaporated to small volume. The formed suspension was filtered through glass frit (G3), and the precipitate was washed with 2×15 ml of n-hexane and then dried in vacuum. Again, the mother liquor was evaporated to give a yellowish oil which was re-crystallized at −30° C. for two months. Crystals precipitated from this solution were collected and dried in vacuum. Thus, 12.2 g (80%) of the title product was isolated. Assignment in NMR spectra was made using the following abbreviations: L1 for 4-(4-tert-butylphenyl)-2-methyl-1H-inden-1-yl and L2 for 6-tert-butyl-4-(3,5-di-tert-butylphenyl)-5-methoxy-2-methyl-1H-inden-1-yl.

Provenance & Evidence