反应详情

A 500 ml 5-neck round-bottom flask, inertized with nitrogen and fitted 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 65 g of Isopar E (isoparaffinic hydrocarbon mixture with a boiling range of 113-143° C., available commercially from ExxonMobil). The water separator is filled to the brim with Isopar E. Accompanied by stirring at 350 rpm, a solution of 30.9 g (0.47 mol) of potassium hydroxide (85% form, available commercially from AppliChem) in 19.8 g of demineralized water is metered in over 10 minutes. In the course of this metered addition, the reaction mixture heats up to 69° C. It is brought by further heating to boiling temperature, and the stirrer speed is reduced to 50 rpm. The distillate separates off as the bottom phase in the water separator. Up to a boiling temperature of 121° C., 64.9 g of clear colorless distillate accumulate, containing—according to analysis by gas chromatography—83.3% of methanol, 14.6% of water, and 1.7% of Isopar E. The hydrolysis of the methoxy radicals in the methyltrimethoxysilane is therefore quantitative. During the distillation, a pastelike white solid separates out in the reaction mixture, and breaks down increasingly into fine particles and forms a suspension. The suspension is filtered through a Beco KD3 filter plate in a pressure suction filter, and nitrogen is passed through until the weight is constant. This gives 61.1 g of fine, white, free-flowable powder with a solids content of 100% (determined using the HR73 halogen moisture analyzer from Mettler Toledo at 160° C.). A 50% strength aqueous solution prepared with this solid exhibits no precipitation even after storage at room temperature for two weeks in the absence of air.

1. customA 500 ml 5-neck round-bottom flask, inertized with nitrogen and fitted with paddle stirrer
2. temperaturewith reflux condenser
3. customis metered in over 10 minutes
4. additionIn the course of this metered addition
5. customheats up to 69° C
6. temperatureby further heating
7. distillationDuring the distillation
8. temperaturea pastelike white solid separates out in the reaction mixture, and breaks down increasingly into fine particles and forms a suspension
9. filtrationThe suspension is filtered through a Beco
10. filtrationKD3 filter plate in a pressure suction
11. filtrationfilter
12. customat 160° C.
13. customA 50% strength aqueous solution prepared with this solid exhibits
14. customno precipitation even after storage at room temperature for two weeks in the absence of air