Acetylsalicylic acid, more commonly known as aspirin, is a widely used pain reliever and anti-inflammatory agent. It was first synthesized by the German chemist Felix Hoffmann in 1897, and has since become an integral part of many households around the world. The synthesis of aspirin involves the acetylation of salicylic acid, a compound that occurs naturally in plants such as willow bark and meadowsweet.
The synthesis of aspirin begins with the conversion of salicylic acid into its sodium salt, which is more reactive and easier to work with. This is typically done by reacting salicylic acid with sodium hydroxide in an aqueous solution. The resulting sodium salicylate can then be acetylated using acetic anhydride as the acetylating agent.
The acetylation reaction is typically carried out in the presence of a small amount of an acidic catalyst, such as sulfuric acid or hydrochloric acid, to facilitate the transfer of the acetyl group from acetic anhydride to the salicylic acid. This reaction proceeds via a nucleophilic substitution mechanism, in which the acetyl group of the acetic anhydride acts as a nucleophile and attacks the electrophilic carbon atom of the salicylic acid.
The acetylated product, known as acetylsalicylic acid, can then be isolated from the reaction mixture by techniques such as crystallization or filtration. It is typically purified by recrystallization to remove any impurities or contaminants that may be present.
The synthesis of aspirin is a simple and efficient process that has been widely used for over a century. In addition to its use as a pain reliever and anti-inflammatory agent, aspirin has also been shown to have beneficial effects on the cardiovascular system, making it a popular choice for preventing heart attacks and strokes. Overall, the synthesis of acetylsalicylic acid has had a significant impact on the field of medicine and has greatly improved the quality of life for many people around the world.
1: Synthesis of Aspirin (Experiment)
From simple essay plans, through to full dissertations, you can guarantee we have a service perfectly matched to your needs. Slower gastric absorption due to increased pH is not reflected in the overall slower absorption. Using 15-HpETE or 15-HETE as a substrate, 5-lipoxygenase can produce 5 S,6 S-epoxy-15-HETE. Due to this, a lack of accuracy occurred in general overall. Williamson, Macroscale and Microscale Organic Experiments, 2nd Ed.
Therefore, the reaction will stop yielding product once the 2 grams of salicylic acid reactant are gone. This causes the solid to begin to form or precipitate. Aspirin is only slightly soluble in water, so if we add it to the reaction mixture, the product would rather clump together than be in the water phase. Allow the flask to cool slightly, and then place in an ice bath to crystallize the acetylsalicylic acid. This could be due to impurities in the product or human error when monitoring and recording the melting point range. Acting centrally, it produces analgesia at a hypothalamic site in the brain, although the mode of action is not known.
In boiling water, 1. Provide structures of all intermediates in your lab report. The TLC plates were examined for reaction completeness. However when 70°C was reached and the heater was turned off, it was observed that the temperature on the thermometer had risen around 10°C more after this point. However compared to the theoretical yield it is evident that there was a great loss of aspirin that should have been formed. This intermediate is metabolized by epoxide hydrolases to yield 5 S,6 R,15-trihydroxyeicosatetraenoic acid lipoxin A 4, LXA 4 or 5 S,14 R,15-trihydroxyeicosatetraenoic acid lipoxin B 4, LXB 4 Scheme 5. One popular drug that does both is aspirin.
Synthesis and Purification of Acetylsalicylic Acid
It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Acid Catalyzed hydrolysis of Aspirin Consider the first step in the acid catalyzed hydrolysis of aspirin shown below; Which of the following is the structure of the intermediate formed in this step? The initial solution in the crystallizer has a volume of 126. In this case, one molecule salicylic acid provides both the "alcohol" and the carboxylic acid. It contains polar functional groups which can form hydrogen bonds with polar water molecules. When the aspirin enters the stomach, some of it absorbs within the stomach. The molecule is an aromatic ring having two functional groups in position also: carboxylic acid is the first substituent and the second is an ester group. Submit the crystalline sample in a small vial with proper labeling to your instructor FERRIC CHLORIDE TEST FOR SALICYLIC ACID Add 10 drops of aqueous 1% ferric chloride solution to a test tube containing a few crystals of the compound to be tested dissolved in 5 mL water and note the color.
Aspirin Stability Aspirin is a popular over-the-counter pain and fever reducer. About 70% of the unchanged aspirin is absorbed in both stomach and in the upper intestine with 30% of salicylate. These can be found under the hypothesis subheading. Therefore precautions were taken with chemicals such as sulphuric acid that causes severe burns. Collect the product by vacuum filtration and rinse out of the flask with a few milliliters of cold petroleum ether. Then, ten drops of 85% phosphoric acid and 5 milliliters of acetic anhydride was added into the Erlenmeyer flask. The reason for this is due to an increase in kinetic energy.
Synthesis of Acetyl Salicylic Acid (Aspirin) Essay Example
Sodium hydroxide reacts with the acetylsalicylic acid but not with the starch binders. In this reaction, a hydroxyl group is converted to an ester, with acetic acid as a byproduct. Acetylsalicylic acid has both anti-inflammatory and antipyretic effects. If the pH of the gastric has risen up to pH 6, there would be a decrease of about 1% of the area of absorption as the majority of aspirin would then be in a less permeable ionized form. It is taken orally as it is well absorbed by the gastrointestinal system. This will be the wet weight. Acidic Mechanism This reaction can occur with acidic or basic conditions.
If mixture solidifies completely, proceed to step 4. Chronic salicylism is often associated with a delay in diagnosis and higher morbidity and mortality. Valproic Acid: Salicylates may increase the serum concentration of Valproic Acid. The phenolic ester bond is susceptible to hydrolysis, especially at alkaline conditions. However, due to the very large surface area for absorption in the intestine, all the aspirin does enter the bloodstream. . Beran, Lab Manual for Principles of General Chemistry, 9th and 8th Ed.
