Methyltrimethoxysilane → methyltrimethoxysilane KOH

Participants

Reaction Conditions

Reaction Steps

A 1000 ml 4-neck laboratory reactor rendered inert using nitrogen and equipped with paddle stirrer, dropping funnel, thermometer, and water separator with reflux condenser is charged with 350 g (2.525 mol) of methyltrimethoxysilane (available commercially from Wacker Chemie AG) in solution in 222.8 g of Isopar E (isoparaffinic hydrocarbon mixture with a boiling range of 113-143° C., available commercially from ExxonMobil). Over the course of 12 minutes, 233.6 g of 50% strength potassium hydroxide solution (0.214 mol KOH) are metered in at 40° C., during which the reaction mixture heats up to reflux (70° C.). It is held at reflux temperature by subsequent heating. The distillate separates out in the water separator as the lower phase, and is continuously taken off and replaced by Isopar E; at the same time, a fine suspension is formed in the reaction flask. Up to a boiling temperature of 118° C., 294.1 g of clear, colorless distillate are collected, which according to analysis by gas chromatography contains 82.4% methanol, 15.7% water, and 1.7% Isopar E. The hydrolysis of the methoxy radicals, accordingly, is quantitative. The suspension is filtered over a Seitz K250 filter plate in a suction filter, and nitrogen is passed through to constant weight. This gives 278.5 g of a very fine, white, free-flowing powder, with a solids content of 99.8% (determined using the HR73 Halogen Moisture Analyzer solids content balance from Mettler Toledo at 160° C.)

Provenance & Evidence