Methanol → methyltrimethoxysilane KOH

Participants

Reaction Conditions

Reaction Steps

A 500 ml 5-neck glass flask, rendered inert with nitrogen and equipped with paddle stirrer, dropping funnel, thermometer, and water separator with reflux condenser, is charged with 50 g (0.36 mol) of methyl-trimethoxysilane (available commercially from Wacker Chemie AG) and 31.8 g of Isopar E (isoparaffinic hydro-carbon mixture having a boiling range of 113-143° C., available commercially from ExxonMobil). Accompanied by stirring at 300 rpm, a solution of 31.8 g of 50% strength aqueous potassium hydroxide solution (0.23 mol of potassium hydroxide) and 2.1 g (0.117 mol) of demineralized water is metered in over 10 minutes. During this metered addition, the mixture heats up to 58° C. It is heated at reflux (66° C.) for an hour and then the distillate is switched to the water separator, which is filled to the brim with Isopar E. Up to a boiling temperature of 118° C., 49 g of colorless, slightly turbid distillate are accumulated, and—according to analysis by gas chromatography—contains 84 area% of methanol, 14 area% of water, and 2 area% of Isopar E. During the distillation, a pastelike white solid separates out in the reaction mixture, and breaks down increasingly into fine particles and forms a suspension. All of the volatile constituents are distilled off with stirring at an oil bath temperature of 70° C. under 5 hPa. This gives 37.3 g of fine, white, free-flowable powder with a solids content of 99.5% (determined using the HR73 halogen moisture analyzer from Mettler Toledo at 160° C.). A 50% strength aqueous solution prepared with this powder exhibits no precipitation even after being stored at room temperature for two weeks in the absence of air. The minimum ignition energy was determined on a powder prepared analogously: up to the maximum possible ignition energy setting of 10 J, there was no ignition in the fluidized dust.

Provenance & Evidence