• Benzoic acids?are the simplest?aromatic carboxylic acids?with the molecular formula of C₆H₅COOH
• Benzoic acids and their derivatives are often used as reagents in the synthesis of?esters
• The compounds can be produced from the?oxidation?of?alkylbenzenes

Oxidation of alkylbenzenes

• The alkyl side-chain in alkylbenzenes, such as methylbenzene, can be oxidised to a?carboxylic acid
• The alkylbenzene is?heated under reflux?with a solution of?hot alkaline KMnO₄?(this is the?oxidising agent)
  • The?purple?colour of the Mn⁷⁺?ions disappears as they are?reduced?to Mn⁴⁺?ions
  • A?brown precipitate?of MnO₂?is formed
• The mixture is then?acidified?with?dilute acid?(such as hydrochloric acid) to?protonate?the organic product form and produce a benzoic acid

Alkylbenzenes such as methylbenzene undergo oxidation to form benzoic acid