Benzene (C25)

Question 1

Nitration of benzene

Answer 1

Benzene + Nitric acid –> Nitrobenzene

Question 2

Nitration of benzene conditions

Answer 2

Catalyst: sulfuric acid
Temp: 50 ºC

Question 3

What happens if excess nitric acid reacts with benzene above 50ºc?

Answer 3

Multiple substituions could be made
- E.g. Create 1,2-dinitrobenzene

Question 4

Bromination of benzene

Answer 4

Bromine + Benzene –> Bromobenzene + HBr
Halogen carrier: FeBr3

Question 5

Chlorination of benzene

Answer 5

Chlorine + Benzene –> Chlorobenzene + HCl
Halogen carrier: FeCl3 or AlCl3

Question 6

Alkylation of benzene

Answer 6

Benzene + Haloalkane –> alkylbenzene + hydrogen halogen

Question 7

Alkylation of benzene example

Answer 7

Benzene + C2H5Cl –> ethylbenzene + HCl

Question 8

Alkylation of benzene conditions

Answer 8

Under AlCl3

Question 9

Acylation of benzene

Answer 9

Benzene + acyl chloride –> aromatic ketone + hydrogen halide

Question 10

Acylation of benzene example

Answer 10

Benzene + ethanoyl chloride –> phenylethanone + HCl

Question 11

Acylation of benzene conditions

Answer 11

Under AlCl3

Question 12

Why are phenols more reactive than benzene

Answer 12

• Lone pair from oxygen is donated into pi-system
• Becomes delocalised
• Increased electron density
• Easier to attract electrophiles