Synthesis Of Vanillin Lab Report

The purpose of this lab is to determine the specific isomer of the bromovanillin produced. In this experiment, vanillin is brominated to produce a mixture of isomers or one single isomer of bromovanillin. The possible product(s) formed are 2-bromovanillin, 5-bromovanillin, and 6-bromovanillin, as seen in Figure 1.1 By utilizing the bromination process of vanillin, one bromovanillin isomer can be formed as a result. As the starting material, vanillin can work with various electrophilic aromatic substitution reactions, due to the presence of aromatic double bonds within the structure. Because of this, three different products (as previously mentioned) are potentially formed.1 The compound created from the reaction can be analyzed to determine

The most common atom to be replaced is a hydrogen atom, but occasionally other atoms may also be swapped out by an electrophile. Within this reaction, the substituents connected to the benzene ring demonstrate directing behavior that can affect the formation of the product. These substituents can either act as an ortho/para or meta director, which ultimately determine where the electrophile is added onto the ring. Figure 2. Bromine Production via Potassium Bromate and Hydrobromic Acid.1
As the name implies, the bromination mechanism in an electrophilic aromatic substitution reaction that replaces an atom on the ring with a bromine atom. The addition of the bromine is driven by the presence of a Lewis acid catalyst and a bromine atom. In most bromination mechanisms, liquid bromine is the preferred reagent to complete the reaction. However, due to potential safety concerns, the aromatic ring was brominated by using a compound of hydrobromic acid and potassium bromate in an acetic acid solution (see Figure 2 for the bromine formation).1 Liquid bromine is known for generating hazardous fumes, so this solution is significantly safer for bromine production. This formation of bromine is crucial for the bromination reaction to