Iodine → tert-Butyldiphenylchlorosilane

Participants

Reaction Conditions

Reaction Steps

48.6 g (2.0 mol) of magnesium filings and a spatula-tip of iodine are initially introduced into a 2 1 three-necked flask with a precision glass stirrer, straight enclosed-scale thermometer, Dimroth condenser and dropping funnel under a blanket of inert gas. By addition of 600 ml of ethylene glycol dimethyl ether and 203.7 g (2.2 mol) of tert-butyl chloride, tert-butylmagnesium chloride is prepared. Initially 5.2 g (0.02 mol) of copper(II) acetylacetonate and then, at 50° C. over 2 hours, 455.8 g (1.8 mol) of diphenyldichlorosilane are subsequently added dropwise. The internal temperature of the flask rises slightly, and the mixture is subsequently stirred at 70° C. for a further 3 hours to bring the reaction to completion. To remove the precipitated magnesium salt from the solution, the reaction mixture is filtered through a pressure suction filter maintained under an argon atmosphere. The filter cake is rinsed with ethylene glycol dimethyl ether. A concluding fractional distillation of the combined filtrates in vacuo gives 420.6 g of tert-butyldiphenylchlorosilane (85% yield, based on the diphenyldichlorosilane) as a colorless liquid in a GC purity of 92%.

Provenance & Evidence