In this case, we have a <u>Friedel-Craft reaction</u> (see figure 1). Usually in this type of reaction, the benzene ring is <u>bonded directly to the carbon that has the halide atom</u>. But in this specific case, this is not happening.
To understand why we have to remember the reaction mechanism of this reaction. As first, step the Cl-C bond attacks the and we form a new bond between the alkyl halide and the , finally the C-Cl bond is broken and a <u>carbocation is formed</u>. In this case, we will have a primary carbocation, a very <u>unstable species</u>. Therefore we will have a <u>methyl shift</u> to obtain a tertiary carbocation.
This tertiary carbocation will react with and continues the reaction. (See figure 2)