Benzenes with chlorosilanes

To prepare multifunctionalized symmetric organosilicon compounds by the polyalkylation of benzene. (2-chloroethyi)trichlorosilane and (3-chloropropyl)tri-chlorosilane were reacted with benzene. Polyalkylations of benzene with (2-chloroethyl)silane and (3-chloropropyl)silane were carried out in the presence of aluminum chloride catalyst at a reaction temperature of 80 C. The reaction of benzene with excess (2-chloroethyI )trichlorosilanes afforded pcralkylated product, hexakis(2-(trichlorosilyl)ethyl)benzene in good yield (70%). ... 

The alkylation of benzene with ((w,a -dichloroalkyl)silanes was also studied in the presence of aluminum chloride catalyst. The alkylation gave diphenylated products, (w.w-diphenylalkyl)chlorosilanes in fair to good yields (Eq. (12)). 

In the alkylation of benzene with (dichloroalkyl)chlorosilanes in the presence of aluminum chloride catalyst, the reactivity of (dichloroalkyl)silanes increases as the spacer length between the C—Cl and silicon and as the number of chloro-groups on the silicon of (dichloroalkyl)chlorosilanes decreases as similarly observed in the alkylation with (cD-chloroalkyl)silanes. The alkylation of benzene derivatives with other (dichloroalkyl)chlorosilanes in the presence of aluminum chloride gave the corresponding diphenylated products in moderate yields.Those synthetic data are summarized in Table XI. 

To examine the decomposition of (triphenylmethyl)chlorosilanes to (diphenyl-methyOchlorosilanes during the alkylations of benzene with (trichloromethyl)-... 

A.s. shown in Table XV, the decomposition of (triphenylmethyl)methyldichloro-silane did not occur at room temperature, but occurred at the reflux temperature of benzene to give (diphenylmethyl)methyldichlorosilane in 10 and 20% yields after I and 2 h reaction periods. The results indicate that the decomposition occurs in the alkylation reaction conditions of benzene with (trichloromethyl)chlorosilanes a.s observed in the decomposition of tetraphcnylmethane to triphenylmethane. ... 

Acid anhydrides can also be used with chlorosilanes (594). If acetic anhydride is used, the produced acetyl chloride is removed by distillation. Via this approach, for instance, chloromethyldiacetoxymethylsilane (595) is obtainable (equation 302)335. Alternatively, Na or Ag carboxylates can react with chlorosilanes in inert solvents like diethyl ether, petroleum ether, benzene, etc.336. 

Vinyldialkylsilanes and vinyltrimethylsilane having no chlorine atoms do not undergo alkylation with benzene derivatives in the presenee of aluminum chloride but vinylchlorosilanes react with benzene to give the alkylation products. The reaetivities of vinylchlorosilanes decrease in the following order vinyl(methyl)di-chlorosilane > vinyltrichlorosilane > vinyl(dimethyl)chlorosilane. 

Carbonation and subsequent hydrolysis of either lithiated or sodiated metallocenes lead to the corresponding carboxylic acids. Ferrocenecarboxylic acid and ferrocene-1,1 -dicarboxylic acid are readily produced in this manner and can be conveniently separated by extraction of the former with ethyl ether or benzene. The reaction of metalated ferrocenes with various chlorosilanes has led to a variety of triaryl- or trialkvlsilylferrocenes (3, 28, 90). 

Head fraction I, which is a mixture of methyldichlorosilane, methyltri-chlorosilane, dimethyldichlorosilane and a small amount of benzene, is separated in the 36-78 °C range and collected in receptacle 16. Then this fraction can enter batch box 4. Fraction II (benzene) is distilled in the 78-82 °C range and collected in receptacle 11, and then poured into receptacle 18. It can be re-used in the synthesis (in this case benzene from collector 18 is sent into batch box 3). Tank residue, which after the distillation of the first two fractions is a concentrate with 50% of methylphenyldichlorosilane, is sent from tank 12 into collector 19 and from there into tank 20, heated with vapour (1.4 MPa). 

TABLE 32. Competing reactions of chlorogermanes and Me3GeCl or chlorosilanes with Grignard reagents in 1 1 ether-benzene"... 

Deshpande et al. [42] replaced water in hydrogel with ethanol (or acetone, cetane). The hydrogel was placed in trimethyl-chlorosilane (TMCS) (solvent is benzene, toluene, or cetane) for modification treatment, and then washed with ethanol. 

A still more stable organophilic surface on silica particles is obtained by reacting the surface with alkyl chlorosilanes, thus attaching organosilyl groups. For example, the surface of colloidal silica was covered with trimethylsilyl groups by Her (460), who transferred silica from water to triethyl phosphate, dried the sol, added trimethyl-chlorosilane, then heated and removed excess reagent and solvent by vacuum evaporation. The solid product was dispersible to form sols in benzene, ether, and chloroform, but not in water. 

Differential conductometric titration has been used [674, 675] for the determination of chlorine in some chloroorganosilane mixtures. The method is based on the quantitative conversion of the chlorosilanes into the alkylthiocyanato derivatives by the action of ammonium thiocyanate, followed by conductometric titration in methyl cyanide/ethyl ether (2/3) solvent with 0.1 N amidopyrine in benzene. The monosub-... 

Napthyl dimethyl (dimethylamino) silane (preparation). A10% solution of 1 equiv monochlorosilane (naphthyl dimethyl chlorosilane) in hexane (in benzene if necessary for solubility reasons) is stirred in a flask equipped with a reflux condenser cooled at -20 °C. From a communicating flask 2.2 equiv of dimethylamine vapour is slowly introduced over the solution and the mixture kept at room temperature overnight. After filtration and evaporation of the solvent, the residue is distilled. 

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