Multistep Synthesis of Benzilic Acid from BenzaldehydeCambria M. MillerMarch 24, 2014Texas A&M University at Galveston, Galveston, TexasINTRODUCTIONBenzilic acid (fig. 1) is a white crystalline solid often used in the organic synthesis of certain pharmaceuticals and medicines (1). It is believed that benzilic acid may have success in anti-aging products. Benzilic acid is an alpha hydroxy acid and other alpha hydroxy acids have been used in a similar manner (2). Figure 1. Structure of benzilic acid. The aim of this experiment was to successfully synthesize benzilic acid from benzaldehyde. Benzaldehyde is an organic molecule used to make bitter almond oil and to synthesize many different organic compounds (3). This experiment is a multistep synthesis, meaning there are multiple parts that require the product from the previous step to be used as a reactant in the next step. So it is very essential to have high yields and precision at each stage. Traditionally, cyanide was used as a catalyst in this reaction since Von Liebig first discovered it during his research on almond oil. However, cyanide is very toxic and harmful to health. More recently, it was discovered that vitamin B1, a coenzyme called thiamine hydrochloride, could be used to catalyze the condensation of benzoin, which is preferable to using cyanide. This experiment will test whether thiamine can effectively catalyze reaction (2). The experiment begins with the condensation of benzoin (equation 1). In the presence of the catalyst thiamine, the 2 benzaldehyde molecules condense to produce benzoin when heated with sodium hydroxide and ethanol. Equation 1: Condensation of benzoin. The production of benzil (equation 2) is a reaction redox. The b...... middle of paper ......uced in Part C using the product from Part B. Another source of error was that on two different occasions the recrystallization was omitted of the procedure. Although it probably won't have a huge effect, crystallizing the product helps remove impurities. The overall product yield for this reaction is 90.53%. Although this number seems high, indicating a very successful synthesis, it does not take into account that Part C began with a new sample of benzil. If the Part B product had continued to be used, the yield would be much lower. Product may have been lost due to residues left in different glassware used due to inefficient transfer as well as unfinished reactions. The aim of this experiment was to produce benzilic acid, not to have high yields so in that sense there was success (excluding the formation of benzil).