16.0 Friedel-Craft's alkylation

  Alkyl Halides and Aryl Halides

The reaction between chlorobenzene and methyl chloride gives $p$-chlorotoluene as major product and $1$-chloro-$2$-methylbenzene as the minor product.

Mechanism

Step 1: Generation of alkyl carbocation (electrophile)

Step 2: Attack of carbocation at ortho and para positions

Step 3: Loss of proton, formation of $2$-alkylchorobenzene and $4$-alkylchlorobenzene