In the electrophilic substituion of benzene ring, the second substituent is directed by the group already present. Electron releasing groups (+I and +M) are ortho-para-directing and activating, whreas the electron withdrawing groups (-I and -M) are meta-directing and deactivating.
Halogens are placed under the category of +T (Tautomeric) groups because they have -Ibdyctuve abd +Mesomeric effect. These groups are deactivating but ortho-para-directing.
In the introduction of third group to the benzene ring, the product of minimum steric gindrance is formed.
Which of the following substituted benzene derivatives would furmish three isomers when one more substituent is introduced ?
A.
B.
C.
D.
