Preparation of chlorinated phenylchlorosilanes

In the absence of catalysts phenylchlorosilanes do not chlorinate even at increased temperature (150-200 °C). It should be kept in mind, however, that the replacement chlorination of phenylchlorosilanes depending on the conditions of the reaction (the presence of a catalyst and its composition, the effect time of chlorine, temperature) is accompanied by breaking up the Si—Car bond  

This secondary reaction is especially noticeable in the presence of catalysts, metal halogenides, which are ranged by their dearylising effect as 

The chlorination of phenyltrichlorosilane with chlorine on heating and in the presence of SbC13 or Fe proceeds according to the mechanism of elec-trophylic substitution of the hydrogen atom in the phenyl radical with chlorine  

When Fe is used as a catalyst, chlorine interacts with the catalyst in the first place  

The chlorocation formed in this case detaches a proton from the phenyl radical in phenyltrichlorosilane and occupies its place  

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