Methyltrimethoxysilane → methyltrimethoxysilane KOH

Participants

Reaction Steps

A 500 ml 5-neck round-bottom flask rendered with nitrogen and equipped with paddle stirrer, dropping funnel, thermometer, and water separator with reflux condenser, is charged with 75 g (0.55 mol) of methyltrimethoxysilane (available commercially from Wacker Chemie AG) and with 65 g of Isopar E (isoparaffinic hydrocarbon mixture with a boiling rate of 113-143° C., available commercially from ExxonMobile). The water separator is filled with the brim with Isopar E. With stirring at 350 rpm, a solution of 30.9 g (0.47 mol) of potassium hydroxide (85% purity, available commercially from AppliChem) in 19.8 g of demineralized water is metered in over 10 minutes. During this addition, the reaction mixture warms up to 69° C. It is bought to boiling temperature by subsequent heating and the stirrer speed is reduced to 50 rpm. The distillate separates out at the lower phase in the water separator. Up to a boiling temperature of 121° C., 64.9 g of clear, colorless distillate are collected, which according to analysis by gas chromatography contains 83.3% methanol, 14.6% water, and 1.7% Isopar E. The hydrolysis of the methoxy radicals in the methyltrimethoxysilane, accordingly, is quantitative. During the distillation, a pasty white solids separates out in the reaction mixture, and increasingly breaks down into fine particles and forms a suspension. The suspension is filtered over a Beco KD3 filter plate in a suction filter, and nitrogen is passed through to constant weight. This gives 61.1 g of fine, white, free-flowing powder, with a solids content of 100% (determined using the HR73 Halogen Moisture Analyzer solids content balance from Mettler Toledo at 160° C.)

Provenance & Evidence