Preparation of Benzyl From Benzoin

The oxidation of benzoin with a mild oxidizing agent results in the formation of α-diketone, benzyl. The concentrated nitric acid is mainly used as an oxidizing agent in this reaction.

Oxidation

Pour 4 grams of benzoin mixture and 14 milliliters of concentrated nitric acid in a round-bottom flask. Heat the mixture on the heating mantle until no more reddish brown NO2 gas is apparent on the reaction mixture. Stir the reaction mixture continuously using a stirring bar. Perform the reaction in a fume hood to vent NO2 produced during the reaction.

Cooling

Remove the heating mantle and allow the mixture to cool for about five minutes. Add 75 milliliters of water to the reaction mixture. Stir the reaction mixture with the stirring bar to coagulate the precipitated product

Collection

Remove the yellow solid using a pipette. Wash the yellow solid with water. The yellow solid product obtained is benzyl.

References

• Miracosta college: Multi-step Synthesis Coenzyme Catalyzed Synthesis of Benzoin and Derivatives