The reaction of toluene with chlorine in the presence of ferric chloride gives predominantly

o- and p-Chloro toluene

The correct answer is option 4. o- and p-Chloro toluene.

If a monosubstituted compound is treated with an electrophile, it will undergo electrophilic aromatic substitution reaction and form a disubstituted compound which may be recognized using the descriptors ortho, meta, and para. If the relative yield of the ortho product and the para products are greater than that of the meta product, then the substituent present in the monosubstituted ring is named an ortho, para directing group.

As we know that the electron donating groups are usually ortho/para directors for electrophilic aromatic substitutions, whereas electron withdrawing groups are usually meta directors. The halogens are ortho/para directors since they need lone pairs of electrons to share with the aromatic ring.

We have to remember that the electron donating group are referred to as activating groups, though steric effects can interfere with the reaction. An electron withdrawing group has the opposite effect on the nucleophilicity of the ring. The electron withdrawing group takes away electron density from a Pi system, thereby making it less reactive during this kind of reaction and thus called as deactivating groups.

When toluene reacts with chlorine in the presence of ferric chloride it gives o-chlorotoluene and para-toluene and hydrochloride as the products. The major products formed in this reaction are o-chlorotoluene and p-chlorotoluene.

We know that the methyl group present in the benzene ring is ortho and para directing. Since the methyl group activates the ring at the para and ortho position much more than the meta positions, the electrophilic substitution reactions occur at these positions. We can write the chemical reaction as,