Chlorotrimethylsilane → HCID 10592115, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 5-acetyl-7-tert-butyl-2,3-dihydro-3,3-dimethylbenzo[b]furan (2.46 g, 10.0 mmol) in 25 mL of anhydrous THF is added dropwise to lithium diisopropylamide (6.0 mL, 12.0 mmol, 2.0M solution in heptane-THF-ethyl benzene) at -78° C. The resulting solution in stirred at -78° C. for 15 min, and chlorotrimethylsilane (1.5 mL, 12.0 mmol) is introduced. The reaction mixture is stirred at -78° C. for 15 min, warmed to room temperature, stirred for 1.5 h, quenched with water, and extracted with ether. The extract is dried over anhydrous sodium sulfate and concentrated in vacuo; the residue is dissolved in 25 mL of anhydrous THF and reacted at 0° C. with N-bromosuccinimide (1.78 g, 10.0 mmol). The resulting yellowish solution is kept at 0° C. for 0.5 h, warmed to room temperature, stirred for 0.5 h, quenched with water, and extracted with ether. The extract is dried over anhydrous magnesium sulfate and concentrated in vacuo. Purification of the residue by flash column chromatography on silica gel (5%→20% ether-hexane) affords about 2.85 g (88%) of 5-bromoacetyl-7-tert-butyl-2,3-dihydro-3,3-dimethyl-benzo[b]furan as a yellowish solid: mp 54-56° C.

Provenance & Evidence