The synthesis of aspirin

Aspirin is a most widely bought and used drugs for pain, fever and inflammation. Its main ingredient, salicylic acid, is irritating to the stomach and the drug must be modified. This experiment synthesizes aspirin with the use of salicylic acid as reactant. The experiment yielded a more acceptable, less irritating drug.

Background of Experiment and Lab Concepts

Present records say that more than 15,000 pounds of aspirin are sold daily (Smith n.d.). It is effective in relieving or reducing different body pains. The first to successfully synthesize it was Charles Frederic Gerhardt in 1853 by creating acetylsalicylic acid but did not market his discovery. A German chemist Felix Hoffman in 1899 who worked for the Bayer Company picked up Gerhardt's concept. It worked on his father's arthritis and Hoffman convinced his company to market the amazing drug. It was patented with the name aspirin on February 27, 1900 (Smith).

This experiment will synthesize aspirin using salicylic as the limiting reactant with acetic anhydride. The synthesized product will be kept for a week in a locker to allow the crystals to dry. The dried product will be weighed a week later to determine the resulting amount of aspirin. The theoretical and actual results will be compared to come up with the percentage yield. Adding the reactants in the molar ratio in a given equation by stoichiometry and allowing the reaction to complete will bring out only products at the end of the experiment. But adding more of one of the reactants will yield a greater amount of aspirin, which will be determined by the moral amount of that reactant, which was not previously present in the greater amount. The limiting reactant determines the actual product amount.

3. Lab Data

A 400-ml beaker is half-filled with ice water and enough tap water is added to cover the ice. Place 60 ml into a 150 beaker and coll it in the ice-water. An empty plastic tray is placed on the balance pan and 2 to 2.2 grams of the salicylic acid is scooped into the tray and the mass of salicylic acid is recorded. The salicylic acid is then transferred to a 125-ml Erlenmeyer flask. Place 4 ml of acetic anhydride into the Erlenmeyer flask, mix and record the volume of acetic anhydride added. Add 5 drops of concentrated sulfuric acid / The salicylic acid should completely dissolve and result in a clear mixture. Go on swirling it. Place 1-2 ml chilled RO/DI water to the flask from a 10-ml graduated cylinder to decompose unreacted acetic anhydride. Mix and swirl with every addition of water. Set up you're your vacuum filtration apparatus. Add now 25 ml chilled RO/DI water to the reaction mix in the flask. Break lumps with a glass stirring rod. Weigh and record the mass of the filter paper. On the Buchner funner, moisten it with 1-2 ml of the RO/DI water. Turn on the aspirator so the moisture in the tunnel would go into the filter paper and seal it to the funnel. Swirling the mixture, pour it into the funnel at the center of the filter paper. With the aspirator on, rinse the aspirin with 15 ml of the chilled RO/DI water and keep it on for 10 minutes to drain the aspirin as much as possible. Then remove the clamp from the tubing to release. Transfer the filter paper and crystals into a weighed watch glass and store until completely dry.