Grignard Reagent

In this experiment, the production of a Grignard reagent (phenylmagnesium bromide) was performed from a bromobenzene reactant combined with magnesium and ether. Phenylmagnesium bromide was then transformed into a tertiary alcohol called triphenylmethanol, through addition of another compound called benzophenone, as well as additional ether. The end product of triphenylmethanol was analyzed via NMR and IR.

Figure 1: Preparation of the Grignard agent by combining bromobenzene with magnesium and ether to produce phenylmagnesium bromide.

Figure 2: Production of triphenylmethanol by combining benzophenone and the Grignard reagent.

Introduction Grignard reagents are important due to their ability to form carbon-carbon bonds through conversion of a ketone (benzophenone) into an alcohol via nucleophilic addition. However, a Grignard agent must first be produced. This was also done through a “Grignard reaction”, which involved combining bromobenzene and magnesium with ether to produce phenylmagnesium bromide
While Grignard reagent was successfully produced, the production of adequate amounts of triphenylmethanol was unsuccessful. Grignard reagent synthesis was successful as evidenced by the signs of a chemical reaction occurring in the second half of the experiment aligning with expectations, such as the pink color displayed in figure 4. However, not enough triphenylmethanol was produced to perform analysis such as NMR and IR, so a stock sample of it was used to perform analysis. This may have occurred due to a presence of water or excessive amounts of dehydrating agent being used, which would have caused triphenylmethanol to degrade. However, analysis of the stock sample was still performed, and showed that the stock sample was very