Continuous and Batch Organomagnesium Synthesis of Ethyl-Substituted Silanes from Ethylchloride, Tetraethoxysilane, and Organotrichlorosilane for Production of Polyethylsiloxane Liquids. 2. Continuous One-Step Synthesis of Ethylethoxy- and Ethylchlorosilanes

Development of a continuous one-step manufacturing process for ethylethoxy- and ethylchlorosilanes is described. The methodology of synthesis of ethyl-substituted silanes has been improved. The important factors for the successful synthesis have been determined. Among them are (1) the replacement of some tetraethoxysilane 3 by ethyltrichlorosilane 10, (2) the optimum concentration of 3 and 10, (3) the excess of the granulated magnesium (the supply rate 50−110 g h - 1 ), and, finally, (4) the columnar apparatus with the stirrer, resulting in high yields of di- and triethylsilanes, low duration of synthesis, and high selectivity of Grignard reagent. Continuous one-step synthesis has been assimilated into industry (up to a scale 7−40 kg h - 1 of magnesium) for production of oligoethylsiloxanes with low (5−20%) and high content (up to 40%) of the terminal triethylsiloxy groups. The rules for R/D process of the Grignard synthesis are described.