Part 4

• Synthesis of 'Oil of Wintergreen'

  1. Weigh approximately 0.5g of salicylic acid and place in a test tube

  2. Add 5ml of methanol to the test tube and gently shake until all salicylic acid has dissolved

  3. Carefully add 10 drops of concentrated sulphuric acid (H2SO4) to the test tube

  4. Stir the contents in the test tube with a stirring rod

  5. Place the test tube in the water bath for approximately two minutes

  6. Remove the test tube from the water bath and carefully sniff the contents. If you smell wintergreen then you have made methyl salicylate

  7. Measure and record the volume of the oil of winter green
• Acetylsalicylic acid (CH3COCH3COOH)


  Aspirin, the ubiquitous pain reliever
• Aspirin


  • It is both an aromatic acid and an ester
  • It is an excellent showcase for at least two or three principles of organic chemistry
• Salicylic acid (C6H4OHCOOH)


  Aspirin's parent compound, a natural analgesic present in the leaves and bark of certain plants
• Salicylic acid is generally unsuitable for internal use, since it is a strong gastric irritant and can cause internal bleeding
• Aspirin was synthesised to avoid the problem of salicylic acid causing damage in the digestive tract, as the acetylated molecule does not cause as much damage
• Salicylic acid forms coloured complexes with Fe ions