Microscale Synthesis of Acetylsalicylic Acid

Ever wonder about the chemical makeup of tablets that people take for pain relief? Before a tablet can be successfully made, the limiting and excess reactants must be considered. The limiting reactant will affect the amount of the product that can be made. Another reason why the starting reactants must be determined carefully is to make reduce the amount of the reactant in excess so that reactants are not wasted. This experiment uses an Alka-Seltzer tablet. Alka-Seltzer dissolves in water and is an antacid and a pain reliever1. The Alka-Seltzer tablet has many uses such as relief of headaches, ingestion, heart burns, or even upset stomachs2. The active ingredients in an Alka-Seltzer tablet is aspirin, also known as acetyl-salicylic acid (C8H12O4), citric acid (C6H8O7), and sodium bicarbonate (NaHCO3)2. The aspirin in the Alka-Seltzer tablet helps with pain relief. Because of the acid-base chemistry (Brønsted-Lowry), citric acid and sodium bicarbonate produce O2, which makes the tablet fizz when it is dropped in liquid. The Brønsted-Lowry theory shows how the Brønsted-Lowry acid donates a hydrogen ion while the Brønsted-Lowry base accepts the hydrogen ions3. The remaining NaHCO3 that is in excess post reaction with the citric acid is what is used to neutralize stomach acid which helps relief heart burn2. The problem in

In experiment two, the drug Panacetin was separated by a series of chemical reactions into its three components: sucrose, aspirin, and an unknown active ingredient, either acetanilide or phenacetin. The purpose of this lab was to determine what percentages of each component is present in the pain-killer. The initial step was to dissolve Panacetin in dichloromethane. However, sucrose is insoluble in dichloromethane because organic molecules are soluble in organic solvents, and dichloromethane is an inorganic solvent, so only aspirin and the unknown dissolved. By using gravity filtration, sucrose was filtered from the solution and 0.30g of solid was collected.

As detailed in Pavia 's Organic Laboratory techniques the reaction is expected to proceed via the following reaction:

Both Aspirin and the Unknown are soluble in dichloromethane, due to their non-polar characteristics. To separate the two components, sodium bicarbonate was added (see figure 3). Sodium bicarbonate reacted with aspirin and converted it to a salt, also forming water and carbon dioxide. It was observed that the solution "fizzed" when this reaction took place, showing the release of carbon dioxide. The newly formed salt then traveled to an aqueous layer where it was soluble, while the unknown remained in the dichloromethane layer. The two layers were then separated. To collect an aspirin solid, the combination of the addition of HCl and the process of vacuum filtration helped to break down the salt and form a solid. Then the solid was placed in the Fisher Scientific Biotemp Oven to dry it to a constant mass of 0.091 g, 32.97% of the total composition. The

Aspirin, Caffeine and Salicylamide were extracted from an over-the-counter pain reliever (BC Powder). These components were separated by manipulating their solubilities by adjusting the acidity and basicity of the solution. By doing this, the three components were forced into conjugate acid (or base) forms, causing selective solubility in either an aqueous or organic solvent. These layers were then separated by use of a separation funnel. Once separated, the components extracted were characterized by measuring the melting point and performing a TLC analysis. Also, the recovered aspirin from the first part of the experiment was recrystallized and compared to that of the

Pre-Lab: Analgesic drugs are known for reducing pain, while antiseptic drugs reduce symptoms such as fevers and swelling. However, some of these drugs can reduce both illnesses. To obtain a pure compound in these drugs, the scientist needs to separate the desired compound by taking advantage of the different physical and chemical properties. Such as; different boiling points, melting points and their solubility properties. To do this a chemist can also asses the differences between acidic and basic substances when they are added to water soluble mixtures. Within this current experiment I will asses the

Aspirin is one of the most consumed painkillers created up to this date due to its reliability and low expense. It is often used to relieve minor aches and pains, reduce fever and as an anti-inflammatory medication. Due to its wide range of uses, the demand for this pharmaceutical is very high. As a result, manufacturers who produce this drug must be efficient in order to reduce the time taken to produce this drug and produce the in very high quantities.

Acetic Anhydride and p-Aminophenol were heated in a vial attached to an air condenser to synthesize crude acetaminophen, resulting in 0.097 grams (47.48% yield). The crude acetaminophen was then recrystallized in a solvent of water and methanol over heat resulting in 0.082 grams (39.61% yield) of pure acetaminophen. Melting points of both crude and pure acetaminophen were taken, and found to be 165.9 - 170.9°C and 168.2 - 171.5°C, respectively. The literature melting point of acetaminophen is 169.5 – 171.0°C, indicating that our final product was pure.

The earliest known use of aspirin was found in the bark of willow trees, in powder form. According to an article “ Aspirin was first produced 110 years ago, but the natural form, salicylic acid, found in plants ( i.e. the willow and myrtle) has been used for thousands of years.”(Aspirin in the Ancient World) Aspirin in this form was mostly used in the ancient world to reduce pain and fevers. During the Victorian era, the natural form of aspirin was associated with an awful taste and often induced upset stomachs and vomiting. Due to this finding, in 1853 a scientist named, Charles Frederic Gerhardt, was able to add an acetyl group to the natural from of salicylic acid. However, this form was said to be unstable. (A Victorian Era Discovery)

Companies manufacturing dyes such as Bayer recognised the potential in pharmaceuticals and began looking into salicylic acid from the barks of willow trees. One chemist from Bayer began looking into salicylic acid because his father was in pain. Salicylic acid is irritating to the lining in the stomach so the chemist used a derivative of the acid that was prepared by another chemist 40 years prior. The derivative was successful and aspirin was created. Now aspirin is the most widely used drug for treating illness and

Independent and controlled variables: The amount of sulfuric acid used for catalysis and the amount of salicylic acid and acetic anhydride.

A 0.5 g of sodium tungstate dihydrate was weighed and transferred into a 50-mL round-bottom flask with a magnetic stir bar. Approximately 0.6mL of Aliquat 336 was then transferred carefully into the round bottom flask using a 1mL syringe. The round bottom flask and its contents were then set up in an oil bath. 11mL of 30% hydrogen peroxide and 0.37 g of potassium bisulphate were added to the reaction mixture in the round bottom flask and stirred using a magnetic stirrer. Lastly, 2.5mL of cyclohexene was added using automatic dispenser and the mixture stirred. A condenser was fitted on the round bottom flask, clamped and attached to water horses. The reaction mixture was then heated on the oil bath and the reflux process initiated for an hour while stirring the mixture vigorously. Half way while rinsing, any trapped cyclohexene in the condenser was rinsed. After 1 hour, the round bottom flask was rinsed

Aspirin (acetylsalicylic acid), caffeine and acetaminophen were isolated from four tablets of Excedrin that had a mass of 2.66 grams. Purity of each component was tested using Thin Layer Chromatography. The tablets were ground and then stirred in Ethyl Acetate to separate the components from their binders. Aspirin was isolated using 5% wt/vol NaHCO3, then caffeine was isolated using 4M HCl. The acetaminophen that remained was washed with deionized water and the Ethyl Acetate solution was kept. The caffeine was deionized with 4M NaOH and put back into a solution of Ethyl Acetate. 4M HCl was used to deionize aspirin and dissolve it into the Ethyl Acetate layer. The extracted aspirin was dried using MgSO4 and placed in a hot water bath to boil off solvent.

c. Aspirin- is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication.

Objective: Students will be able to synthesize aspirin using an esterification reaction and conduct a purity test on the aspirin crystals and a commercial aspirin product.