“Lab Report For The Synthesis of Chalcone”

 

“Lab Report For The Synthesis of Chalcone”

Theory:

Chalcone is synthesized through the Claisen-Schmidt condensation reaction between an aromatic aldehyde and an acetophenone or ketone. The reaction is catalyzed by a base, usually a strong base like sodium hydroxide, and proceeds through the formation of an enolate intermediate. The enolate reacts with the aldehyde to form the chalcone product.

Chemicals Used:

1. Sodium hydroxide (NaOH) - 5.5 grams
2. Water - 50 ml
3. Rectified spirit - 30 ml
4. Ice - 13 grams
5. Acetophenone - 14 ml
6. Benzaldehyde - 11 ml

Apparatus Used:

• Magnetic stirrer
• Glass beaker 
• Stir bar
• Weighing scale
• Filtration setup
• Drying apparatus

Chemical Equation:

Mechanism:

Procedure:

1. Dissolve 5.5 grams of sodium hydroxide (NaOH) in 50 ml of water to prepare a sodium hydroxide solution.
2. Add 30 ml of rectified spirit (ethanol) to the sodium hydroxide solution.
3. Add 13 grams of ice to the solution and stir until it is dissolved.
4. Add 14 ml of acetophenone to the mixture and shake well.
5. Add 11 ml of benzaldehyde to the solution and observe the formation of a milky white mixture.
6. Maintain the temperature below 20°C, preferably by placing the reaction vessel in an ice bath or a cold-water bath.
7. Place the reaction vessel on a magnetic stirrer and stir the solution for 2 hours with the vessel covered.
8. After 2 hours, the solution should become thick and change color from white to yellow.
9. The yellow precipitate formed is chalcone.
10. Filter the chalcone precipitate using a filtration setup (e.g., Buchner funnel) to separate it from the liquid portion.
11. Wash the chalcone precipitate with a small amount of cold solvent (e.g., rectified spirit) to remove impurities.
12. Dry the chalcone product using a suitable drying apparatus (e.g., desiccator) to remove any residual solvent.