Acetaminophen Lab essays

Acetaminophen Lab essays The purpose of this lab was to use our techniques that we have learned so far in lab in order to synthesize acetaminophen from p-aminophenol and acetic anhydride. This lab was also intended to teach us how to isolate and recrystallize our compound in order to get rid of as much impurities as possible and check the purity using the melting points. Lastly, this lab helped us continue to use thin-layer chromatography in order to compare our compound to similar compounds that can be found on the shelf in order to find the active ingredients in the different analgesics. In order to start the synthesis of acetaminophen I did an acid-base reaction by adding concentrated hydrochloric acid to p-aminophenol. The p-aminophenol was then mixed with some charcoal, turning the mixture black, and then filtrated out by gravity. After this I used a buffer solution of sodium acetate to mix with the p-aminophenol and then immediately added 2 mL of acetic anhydride in order to complete the ingredients required for the synthesis. The reaction was then cooled and the crude crystallized acetaminophen was collected by vacuum filtration. I was able to retrieve 1.88g of the crude acetaminophen, which turned out to be a 64.4% yield based on the fact that p-aminophenol was the limiting reactant for this synthesis. The melting point found for the crude was 160-162 degrees Celsius, which is about 20 degrees below the melting point of pure acetaminophen, meaning that the crude product has some impurities. Part B. Recrystallization of Acetaminophen I placed .504g of the crude acetaminophen into a test tube and added boiling water, our solvent, drop-wise until the crude acetaminophen was completely dissolved. This solution was then cooled slowly in order for crystals to form and was then collected by vacuum filtration. The amount recovered from the recrystallization turned out to be .399g, which meant that I recovered 79. ...