Organic Chemistry Quiz#4

Electrophilic aromatic substitution

Electrophillic aromatic substitution mechanism

• the base attacks the hydrogen

Replacing H with electrophiles

Reaction#1

Reaction #2

• replace the hydrogen with NO₃

Why is this position not accessible?

Due to steric effects of the tert-butyl. It is better to put the tert butyl on the para position

IMPORTANT: Both favor the same position so there is only ONE major product

Reaction #3

• the OH group is a strong activator

• methyl group is WEAKLY activated

• when something strong goes against something weak the stuff that is strong is going to win

• add electrophile to STRONG position

Whenever you react benzene with concentrated sulfuric acid (H2SO4) and heat, the reaction will go to the RIGHT and create a sulfuric acid

Reaction#4

Reaction #5

Note: Chlorine is on the MOST accessible position so it it the MAJOR product

Reaction #6

Reaction #7 : Frito’s craft alkylation reaction

• chlorine atom is on a primary carbon and there is a HIGHER substituted carbon next to it

• Benzene ring will go on the MORE SUBSTITUTED carbon

  • the 2 degree one

NO Reaction

• does NOT work if you have a strongly deactivating group like an NO₂ group

• Toluene is more nucleophilic and more reactive than benzene, so toluene is more likely to react with another methyl chloride than benzene. So it reacts AGAIN

• Poly alkylation occurs

Disadvantages/Limitations of Frito Crafts Alkylation

1. Poly alkylations can occur with multiple alkyl groups being added, leading to complex mixtures and reduced selectivity.

2. Carbocation rearrangements

3. Can NOT use Frito Crafts Alkylation when there is a strongly deactivated ring