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Preparation of Aspirin (typical A level procedure) • Pear shaped flask • Bunsen burner • Reflux condenser • Vacuum filtration

Preparation of Aspirin (typical A level procedure) 1. Weigh out 2 g of 2 -hydroxybenzoic acid and place it in a pear shaped flask. (The starting material is a fluffy irritant white solid. ) 4. When it is cool, add two anti-bumping granules. 2. Add 4. 0 cm 3 of ethanoic anhydride. (A colourless liquid with a pungent smell. ) 7. Pour into 100 cm 3 of cold water containing 10 cm 3 of dilute sulphuric acid. Stir and allow the resulting suspension to stand for 15 minutes. 3. The reaction mixture will get slightly warm so cool it by swirling the flask under running water. 5. Heat under reflux for 30 minutes. 6. Cool the mixture. 8. Filter off the crystals that form. Dry and weigh the product.

The chemistry used to make aspirin ethanoic anhydride 2 -hydroxybenzoic acid aspirin

Preparation of Aspirin (typical A level procedure) 1. Weigh out 2 g of 2 -hydroxybenzoic acid and place it in a pear shaped flask. (The starting material is a fluffy irritant white solid. ) How would you do this for 20 kg 10, 000 times the scale?

Preparation of Aspirin (typical A level procedure) 1. Weigh out 2 g [20 kg] of 2 -hydroxybenzoic acid and place it in a pear shaped flask. (The starting material is an irritant fluffy white solid. )

Preparation of Aspirin (typical A level procedure) 4. 0 cm 3 2. Add [40 litres] of ethanoic anhydride. (A colourless liquid with a pungent smell). Temperature probe

Preparation of Aspirin (typical A level procedure) 2. Add 4. 0 cm 3 [40 litres] of ethanoic anhydride. (A colourless liquid with a pungent smell).

Preparation of Aspirin (typical A level procedure) 3. The reaction mixture will get slightly warm so cool it by swirling the flask under running water.

Preparation of Aspirin (typical A level procedure) 3. The reaction mixture will get slightly warm so cool it by swirling the flask under running water.

Preparation of Aspirin (typical A level procedure) 3. The reaction mixture will get slightly warm so cool it by swirling the flask under running water.

Preparation of Aspirin (typical A level procedure) 4. When it is cool, add two anti-bumping granules. 5. Heat under reflux for 30 minutes.

Heat under reflux for 30 minutes 140 120 °C 100 80 60 40 20 30 60 90 120 Time in minutes 150 180

Preparation of Aspirin (typical A level procedure) 5. Heat under reflux for 30 minutes. The maximum transfer of heat from the fluid in the jacket to the reaction mixture is 2° per minute Condenser

Heat under reflux for 30 minutes 140 120 °C 100 80 60 40 20 30 60 90 120 Time in minutes 150 180

Preparation of Aspirin (typical A level procedure) 6. Cool the mixture. 7. Pour into 100 cm 3 [1000 litres] of cold water containing 10 cm 3 [100 litres] of dilute sulphuric acid. Stir and allow the resulting suspension to stand for 15 minutes. 8. Filter off the crystals that form. Dry and weigh the product. Condenser

Preparation of Aspirin (typical A level procedure) 8. Filter off the crystals that form. Dry and weigh the product.

Filter off the crystals that form

Dry and weigh the product