directing groups

Question 1

What is the order of reactivity for benzene, nitrobenzene and phenol

Answer 1

• least reactive is nitrobenzene which needs a high temperature and halogen carrier catalyst
• second most reactive is benzene, which needs a moderate temperature (50 degrees) and catalyst (such as concentrated sulphuric acid)
• most reactive is phenol/ amine which reacts at room temperature without a catalyst

Question 2

How does Nitrogen oxide functional group direct other groups in the benzene ring and why??

Answer 2

It is 3 directing (directs additional groups to position 3), because the functional group is very electronegative and DEACTIVATES the ring, making it less susceptible to electrophilic attacks

Question 3

How does OH / NH2 groups direct other groups in the benzene ring and why??

Answer 3

It is 2-4 (6) directing, because the lone pairs of electrons interact with the benzene ring, increasing the availability of electrons by increasing density, known as ACTIVATING the ring, making it more susceptible to electrophilic attacks