Benzene

Benzene

1. Phenol

   • Acts as a weak acideg partially disociates in water and doesn't react with weak bases
     • C6H5OH + H2O => H3O+ + C6H5O-
     • C6H5OH + NaOH => C6H5O-Na+ +H2O
   • Adds electrons into the delocalised ring of elecltrons so promotes substituitions in the 2,4,6 positions
   • Direct Halogenation
     • Phenol, 3Br2 , room temp to make 2,4,6 tribromo phenol + 3HBr
   • Nitration
     • single- room temp dilute HNO3 2 or 4 position
     • 2,4,6 trinitrophenol made ic HNO3 is conc
   • HaloPhenol
   • Nitophenol
     • Nitrobenzene has a 3 directing effect as it withdraws electrons from the Pi system ie makes 3 bromo nitrobenezene
     • Aromatic amine ie Phenylamine
       • Phenylamine shows 2- 4- directing effect with 3Br2 to make 2,4,6 tribromophenylamine + HBr
     • Reduction
       • Tin, conc HCl, in situ reducing agent, reflux 100C, strong alkali added ie NaOH 30 mins later to neatralise excess acid. Then seperated using steam distillation, solvent extraction, and further distillation

2. Electrophilic Substitution of benzene- electrophile is attracted to electron dense benezene

   • Nitrobenzene/Arenes
     • Reduction
       • tin conc HCl reflux at 100C then strong alkali NAOH added to neutralise excess acid. Obtained through steam distillation solvent extraction,and further distillation
         • C6H5NO2 + 6[H] = C6H5NH2 + 2H2O
   • Halobenzene
   • Benzene with a alkyl chain
   • Acylation
     • 60 C reflux halogen carrier anhydrous RCOCl
   • Benezene with C(=O)R
     • eg benzaldehyde
       • Oxidation
         • Benzoic Acid
           • Benzoyl Chloride
           • Nucleophilic Substitution
             • PCl5
           • Benzonitrile
             • Hydrolysis
               • H2O HCl
   • Nitration
     • HNO3, H2SO4 (NO2+)
   • Halogenation
     • Halogen carrier ALCl3 FeCl3 or Fe, ( Cl+)
   • Alkylation and Friedel Crafts
     • Halogen carrier eg AlCl3, Haloalkane cation
   • Phenylketone