Reactions of Benzene and Methylbenzene

Reactions of Benzene and Methylbenzene

1. Nitration

   • Benzene + Nitric Acid
     • nitrobenzene + water
     • conc nitric , conc sulphuric (catalyst)
     • reflux 55c
   • methylbenzene + nitric acid
     • 2-nitromethylbenzene + water
     • conditions same as yellow
     • CH3 electron releasing directs to position 2 and 4

2. Reactions of Chlorine and Bromine

   • benzene + chorine
     • chlorobenzene + hydrochloric acid
     • reflux
     • Cl2 and Br2 must not be aq
     • Anhydrous AlCl3, halogen carrier, lewis acid, catalyst
     • same reaction with Br2 but use anhydrous FeBr3
     • other halogen carriers : Fe, FeCl3, FeBr3
   • methylbenzene + chlorine
     • 2-chloromethylbenzene + 4- chlormethylbenzene + HCl
       • Anhydrous AlCl3 (halogen carrier)
       • Cl2 must not be aq
       • Same reaction with Br2 but use FeBr3
     • methylchlorobenzene + HCl
       • UV light or heat
       • free radical substitution
       • Same reaction with Br2
   • electrophilic substitution

3. Oxidation of Methylbenzene

   • methylbenzene oxidises to benzoic acid
   • heat under reflux
   • reagents: KMnO4/ H+

4. Preparation of Methylbenzene

   • Friedel Crafts Alkaltion
   • methylbenzene + HCl
   • anhydrous AlCl3
   • room temp, dry ether

5. Benzene + Hydrogen

   • forms cyclohexane
   • nickel catalyst
   • very high pressure and temperature
   • addition reaction