Production of Aspirin (BioChem)

  the synthesis of aspirin involves: the acetylation of salicylic acid with acetic anhydride. For example, catalysts are crucial to the mechanism, because this is a nucleophilic substitution reaction at a carbonyl carbon. Additionally, the utilization of a general acid catalyst (sulfuric acid), which will protonate the carbonyl oxygen: allowing it to be more susceptible to attack. Similarly, a Lewis acid catalyst will be used to deliver a similar response, specifically: boron trifluoride etherate. Alternatively, there will be use of a Lewis base catalyst (pyridine), which will be used to react with the acetic anhydride to generate a reactive species. Lastly, the final catalyst/general base catalyst, will complete its function via proton abstraction at an intermediary stage. For instance, the catalyst is sodium acetate. Finally, this experiment will use quantitative measures to calculate the relative catalytic ability for the reaction. For example, this exothermic reaction will use an arbitrary temperature rise of approximately 4 Celsius. Which will be an indicator, that an equivalent amount of reaction was undergone. All in all, this experiment serves as a real world application of the synthesis of aspirin, a prominent drug in the pharmaceutical industry. Moreover, the catalysts utilized in this procedure will be: sulfuric acid, boron trifluoride etherate, pyridine, and sodium acetate. It is important to note, this experiment is exothermic: the utilization of a 4 Celsius rise will be an indication of a reaction taking place

    The procedure includes:

                        

1.) Setup a test tube rack containing 4 (13x100mm test tubes). 2) place 1g of salicylic acid in each test tube, followed by 2mL acetic anhydride. 3) add .2g of sodium acetate to the first tube and note the time of addition and the temperature of the reaction mixture. 4) While utilizing the thermometer to measure temperature, also utilize the thermometer to gently stir the mixture, noting the time it takes to increase in 4 celsius. 5) Clean thermometer for each test tube use. For the second test tube, add 5 drops of pyridine (make sure not to add sodium acetate). 6) repeat step 4. 7) Once finished with the second test tube, for the third test tube sample, ask the instructor for 5 drops of boron trifluoride etherate: repeating step 4. 8) For the last sample, utilize 5 drops of sulfuric acid repeating the process of measuring a 4 celsius increase alongside the time required. 9) Finally, once finished with each sample test tube, place all 4 test tubes in a hot water bath. 10) do so carefully, for a time of 5 minutes. 11) Once finished, combine all test tube samples in a 125 ml Erlenmeyer flask, containing 50 ml of water. 12) Mix thoroughly and cool in an ice-water bath. 13) Once cooled, utilize a vacuum filtration mechanism to complete the experiment.