Procedure Potassium carbonate (1.108 g, 8.017 mmol) was added to trimethylphosphonoacetate (1.4 mL, 8.688 mmol) and p-methoxybenzaldehyde (365 µL, 3.001 mmol) in a 10 mL flask. The solution was then heated and stirred at 170 degrees Celsius and 1100 RPM until reflux occurred. After being heated under reflux for 12 minutes, the solution was allowed to cool for 10 minutes before being transferred to another flask using 11 mL of water. The crude, flaky product was isolated via suction filtration and dried for 5 minutes and then weighed. After being dissolved in a minimal amount of hot 95% ethanol, crystal formation began again once water was added until the solution looked semi-opaque. After cooling, the flask was placed into an ice bath for …show more content…
This impurity could have come from one of two sources. The primary source is that as lab time ran short, a vial that recently had residue from a previous lab was used without a very thorough cleaning. This would make sense that an extra peak is seen and a peak is seemingly missing if another molecule showed up in the NMR. Secondly, a lot of ethanol was added to the solution when recrystallization was occurring, and the crystals would not form until the sides were scrapped. Using a possibly contaminated spatula that was used to scrape the crude product would mean that some peaks from the original reagents could be seen in the NMR. This issue also affected the percent yield, dropping it to 74.00 percent as the recrystallization process had to be hurried along due to time. A portion of product was also lost from the final yield as some of the product was dropped. In an effort to decrease these in the future, less ethanol should be used when dissolving the crude product, and a funnel could be used when transferring product. Making sure that glassware is always cleaned with time to spare would also be a crucial component to increasing purity of products made in