comparing the reactivity of benzene with phenol

• benzene 


  • pi electrons are delocalised (shared between more than 2 atoms)
  • low electron density
  • when reacted with nitric acid , benzene needs mixture of concentrated nitric acid and concentrated sulfuric acid at 50 degrees celsius to generate $NO_2^+$ electrophile
  • when reacted with bromine, benzene needs halogen carrier catalyst to generate $Br^+$ electrophile
• phenol


  • lone pair of electrons from oxygen p-orbital of the hydroxyl group becomes delocalised into the pi electron cloud of benzene ring
  • increases electron density
  • increased electron density means that electrophiles are attracted more strongly to phenol
  • phenol reacts with dilute nitric acid at room temp
  • phenol reacts with $Br_2$ without the need for a catalyst