• Phenols?are organic compounds characterised by the presence of an -OH group which is attached to a benzene ring
• Phenols can be produced by the reaction of?phenylamine?with?nitrous acid?(HNO₂)

Production of phenol

• Phenols can be prepared from phenylamines under the following reaction conditions:
  • NaNO₃?with dilute acid (to form HNO₂)
  • Ice to keep the temperature below 10?^oC (step 1)
  • Heat (step 3)
• This reaction involves three steps:
  • Step 1?- The HNO₂?is so unstable that it needs to be prepared in a test-tube by reacting sodium nitrate (NaNO₃) and dilute hydrochloric acid (HCl) while keeping the temperature below 10?^oC using?ice

Nitrous acid can be prepared in a test-tube by reacting sodium nitrate with dilute hydrochloric acid

• • Step 2 -?Phenyl amine is then reacted with the HNO₂?to form an?unstable diazonium salt

Formation of an unstable diazonium salt

• • Step 3 -?The diazonium salt is so unstable that it will?thermally decompose?when?heated?to form a?phenol

A phenol is formed upon the thermal decomposition of the diazonium salt