Multistep Synthesis of Benzilic Acid Essay Example

Abstract: The objective of the experiment was to prepare Benzilic acid by multistep synthesis starting with benzaldehyde. In this setup however, product of the first step, Benzoin, is provided thereby omitting the first step involving the conversion of benzaldehyde. For this experiment, the microscale techniques of reflux, crystallization, and melting-point determination were used. Utilizing these techniques a product yield of 93% for benzil and 57% for Benzilic acid was obtained, as well as a melting point range of 94.8 – 95.4oC for benzil and 152.0 – 153.9oC for Benzilic acid. With the literature melting-point value of benzil being 95oC ( Pavia, 2012), the product was deemed of pure enough quality to be used in the preparation of Benzilic acid. The melting point of Benzilic acid was taken twice, the first being155.4 – 156.5oC, and the second being 152 – 153.9oC. Another melting point was taken due to suspicion of a wet product as suggested when compared to the literature value at 150oC (Pavia,2012). The second melting point having decreased from the first indicated that the product was indeed wet however of pure quality nonetheless, concluding the reaction was overall a success.

Introduction:
Overall Reaction: Mechanism: The oxidation of Benzoin to Benzil and conversion of Benzil to Benzilic acid are two of the main steps that make up this multistep reaction. This being a multistep reaction meant that the success of synthesizing the end product Benzilic acid would be completely dependent on the success of every step that came before it. Since Benzil is required to form Benzilic acid, it makes sense then that the first step be the production of Benzil, which was formed from Benzoin. This reaction required the oxidation of the α – hydroxyketone, Benzoin, by Nitric acid. Both reactions in this experiment however required refluxing of the reaction to maintain the amount of solvent and allow the reaction to proceed at a high temperature (Pavias,