4-Bromophenetole → 4-Ethoxyphenyldimethylsilane

Participants

Reaction Steps

A Grignard solution prepared from 481.4 g of 4-bromophenetole, 61.0 g of magnesium and 1820 ml of tetrahydrofuran is added dropwise at -40 ° C. to a solution of 316 g of dichloromethylsilane in 1450 ml cf anhydrous tetrahydrofuran. Stirring is subsequently continued for 1 hour at -40 ° C., and the mixture is allowed to slowly warm to room temperature. After 1175 ml of a 3M methylmagnesium chloride solution in tetrahydrofuran have been added, the mixture is refluxed for 1 hour and cooled to 30 ° C., and the excess Grignard reagent is decomposed by the dropwise addition of 1100 ml of water. The phases are separated, and the aqueous phase is extracted using 500 ml of tetrahydrofuran. The combined organic phases are freed from solvent in vacuo, and the crude product is distilled in a thin-layer evaporator. 417 g of crude product of a purity of 94.3% (GC) are obtained, which corresponds to a yield of 91.1% of theory. The boiling point at 0.012 bar is 78° to 82 ° C.

Provenance & Evidence