Question

The reaction of toluene with \[{\text{C}}{{\text{l}}_2}\] in presence of \[{\text{FeC}}{{\text{l}}_3}\] givex ‘X’ and reaction in presence of light gives ‘Y’. Thus, ‘X’ and ‘Y’ are:
A.X = Benzal chloride
Y = o-chlorotoluene
B.X = m chlorotoluene
Y = p-chlorotoluene
C.X = o- and p- chlorotoluene
Y = Trichloromethyl benzene
D.X = Benzyl chloride
Y = m-chlorotoluene

Answer 1

Hint: When the reaction takes place in the presence of \[{\text{FeC}}{{\text{l}}_3}\] then two products are formed with substitution on active sites. In presence of sunlight it alkyl substitution occurs.

Complete step by step answer:
Toluene is basically methyl substituted benzene. Alkyl group is a ring activating group. It increases the electron density on ortho and para positions of a benzene ring and hence, make it more suitable for electrophilic substitution reaction. The increase in electron density is due to the hyper conjugation of the alkyl group. Hence, when reaction takes place in presence of , which act as a catalyst for reaction, then both ortho and para substituted product form. The Para product form is more stable than ortho product, because of less steric hindrance at para position. So Para substituted chlorotoluene forms in major amounts and ortho substituted forms in minor amounts.
When the reaction takes place in light the substitution occurs on the methyl group instead of benzene ring, hence 3 hydrogen of alkyl group het substituted by 3 hydrogen and trichloromethyl benzene forms.
The products formed are X = o- and p- chlorotoluene and Y = Trichloromethyl benzene.

Hence, the correct option is C.

Note:
\[{\text{FeC}}{{\text{l}}_3}\] along with chlorine leads to the generation of \[{\text{FeC}}{{\text{l}}_3}\] electrophile. An electrophile is that species which is deficient in electrons. Benzene ring is electron rich in nature due to the presence of 3 pi bonds and hence electrophilic reactions occur in case of benzene. The formation of product X above is an example of electrophilic substitution reaction.