Acetic Anhydride Reaction Lab Report

1041 Words5 Pages

Acetylation Lab Summary Two versions of the same experiment were performed to assess the difference in reactivity of certain amines with acetic anhydride. Throughout both experiments, observations were made about the reaction progress. The starting materials and products were characterized using thin layer chromatography (TLC), infrared spectroscopy (IR), and melting point. During the first week, I dissolved 0.512g of aniline in 8.5mL of water, and added 5.5mL of 1M HLC. During this step, I observed that there were bubbles in the solution, especially at the bottom of the beaker. After adding the HLC, there solution had a slight yellow tint. Next, I mixed 0.529g of sodium acetate in 3mL of water and added 0.679g of acetic anhydride to the aniline solution and immediately added sodium acetate. The solution was cooled in an ice bath for fifteen minutes. During this time, I noticed the formation …show more content…

Since my unknown had the presence of a halogen, I narrowed down possible starting materials. I combined all of the characterization data from week 2 and was able to identify my unknown starting material as para-bromoaniline and my product as 4-bromoacetanilide. The melting point for para-bromoaniline is typically 66°C and 168°C for 4-bromoacetanilide. Both of these numbers match with the melting point ranges I obtained. This data, combined with the TLC evidence that my unknowns were more polar, allowed me to reach this conclusion. Additionally, I compared IR spectra I obtained to official IR spectra for para-bromoaniline and 4-bromoacetanilide and they had the same important peaks. Between the two weeks, the reaction time was not very different and was about 15 minutes. The combination of data from TLC, IR, and melting point were able to help me asses the identity of my unknown product, and this the importance of characterization in