The goal of this experiment was to synthesize aspirin. In this experiment aspirin, also known as acetylsalicylic acid, was synthesized from salicylic acid and acetic anhydride. In the reaction the hydroxyl group on the benzene ring in salicylic acid reacted with acetic anhydride to form an ester functional group. This method of forming acetylsalicylic acid is an esterification reaction. Since this esterification reaction is not spontaneous, sulfuric acid was used as a catalyst to initiate the reaction. After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in the solution as well as some sulfuric acid, aspirin, and acetic acid. Crystallization, which uses the principle of solubility, was then used to remove most of the impurities and caused the acetylsalicylic acid to precipitate out of the solution. Next, the crude product was then purified by adding water which further lowered the solubility of acetylsalicylic acid and dissolved some impurities from the crystal of aspirin. The aspirin was then isolated from the solution using a vacuum filtration apparatus. The percent yield of crude aspirin product was 91.89%. To purify the crude aspirin product a recrystallization procedure was performed. The percent yield of the purified aspirin product was 5.77%. Next a phenol test was performed on the crude aspirin product, the purified aspirin product, and salicylic acid as a control. The phenol test was to test the purity of the aspirin product that was created during the experiment. The crude aspirin product and the purified aspirin product had no color changes and remained orange when mixed with the iron (III) chloride solution, which means that there were no phenol groups in both the crude aspirin product and the purified aspirin product. The lack of reaction with the iron (III) chloride revealed that both the crude aspirin product and the purified aspirin product were pure aspirin. The salicylic acid turned into a dark purple color when mixed with the iron (III) chloride solution, which was expected since salicylic acid has phenol groups. Next a melting point test was performed on the purified aspirin product. The purified product started to melt at 86 degrees Celsius and finished completely melting at 102 degrees Celsius. The melting point of the purified product was lower than the expected 135 degree Celsius melting point of aspirin, which revealed to us that the purified aspirin product still contained some impurities.
As early as 3000 BC ancient cultures such as Greek, Roman, Egyptian, and Chinese found that extracts from plants such as willow bark, meadowsweet, and myrtle possessed the ability to alleviate fever, pain, and inflammation. These plants contain a compound called salicylate, which creates these curative attributes. Several of years later the folk remedy of plants containing salicylate transformed into the cure-all medication known as aspirin. Today aspirin, also known as acetylsalicylic acid, is an over the counter medication that is extremely popular and is used for relieving pain, reducing fever, reducing swelling, and slowing blood clotting. The history of aspirin began in 1763 when Edward Stone wrote a paper to the Royal Society of London that claimed that willow bark could cure ague, which is now known as malaria. Later it was found that the treatment did not actually cure malaria, but instead just reduced the fever of those with the disease. Nearly a century later, a Scottish physician found that Edward Stone’s extract could also be used to relieve the symptoms of acute rheumatism. Organic chemists began working with willow bark and many other plants to try and extract and isolate the active ingredients from them, in doing so it was found that the active ingredient was salicylic acid. Salicylic acid was then industrialized for medicinal use, but soon after industrialization it was found that salicylic acid was extremely...
Cited: Aguilar, Andrea. "Synthesis of Aspirin Part B."CourseHero. N.p.. Web. 7 Mar
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