Chlorophenyl silanes

While attempts were made to prepare the ethoxysilanes via the classic Grignard reaction, only phenyldimethylethyoxysilane was prepared in this manner. The Grignard reaction proved to be unsuitable for the preparation of the four para-substitutcd phenyldimethylethoxysilanes either because of sensitivity to Grignard formation or difficulty in isolating the product from the reaction mixture since the by-product salts were unfilterable. Therefore, all four silanes (p-chlorophenyl, p-methoxyphenyl, p-tolyl and p-trifluoromethylphenyldimethyl-ethoxysilane) were prepared via an organolithium reaction. 

Substituted Silanes. 2- (p-CHLOROPHENYL) ETHYLTRICHLOROSILANE, 2-(p-Chlorophenyl)ethyltrimethoxysilane, and 2-(p-Chlorophenyl)-ethyltriethoxysilane. Steps in the synthesis of p-ClC6H4(CH2)2SiCl3 and p-ClC6H4(CH2)2Si(OEt)3 are shown in Scheme III. 

Adsorbed films of ethykriethoxysilane and vinyltriethoxy-silane were formed on silica and alumina by retraction from hydrocarbon solution and their wettabilities and water-stabilities determined. The vinyltriethoxysilane films were generally more oleophobic, more hydrophobic and more resistant to contact with water than the films formed by the ethyl analog. Neither adsorbate formed stable films on a-alumina. The addition of low molecular weight organic acids or bases to the adsorbate solution resulted in both the ethyl and vinyl compound forming hydrophobic and water-stable films on silica and ot-alumina. Films of p-chloro-phenyl-ft-ethyltrichloro, -trimethoxy, and -triethoxysilane were also studied and found to be water-stable and to have wettabilities characteristic of a surface comprised of closely-spaced p-chlorophenyl groups. 

TRICHLORO-l,l-DI-(4-CHLOROPHENYL)ETHANOL see BIO750 TRICHLOROpiCHLOROPHENYL)SILANE see DGF200... 

Franc and Dvoracek showed that some functional groups and bond types may be identified by degradation of the sample in a microreactor, and gas chromatographic separation of the volatile reaction products. Details of the method and apparatus are given, and results are presented for the degradation of alkyl- aryl- and chloralkyl-silanes and siloxanes (with concentrated sulphuric acid saturated with vanadium pentoxide) of alkoxysilanes (with hydriodic acid at 75 C) and of vinylsilanes (by saturation with chlorine on a water bath followed by decomposition with concentrated sulphuric acid at 175°C). Alkyl, chloroalkyl, phenyl, chlorophenyl, alkoxyl and vinyl groups, and s Si-Si s and =Si-H bonds were all detected by these procedures. 

---