Consider the preparation of acetylsalicylic acid aspirin , by reacting salicylic acid with acetic anhydride. Salicylic acid crystals from diethyl ether. All chemicals were disposed of properly. Put each compound in a test tube, added about 1 mL of ethanol, and added 3 drops of 0. Can you identify the limiting reactant in the synthesis? For best results, the hot plate should have a built-in magnetic stirrer to maintain even heating. Add 1mL of cold water to help transfer all of crystallized substance.
The hydrolysis reaction is depicted below: References Hoffman, Lucas. Phenyl salicylate called salol is formed with phenol, which is also used as an antiseptic and antipyretic agent. Introduction Aspirin is among the most fascinating and a versatile drug known to. Calculate amount of acetic anhydride needed amount of salicylic acid times 3 2. Aspirin contains functional groups which can form with polar water molecules. Can you see what effect this had on the end product? To purify our crystals even more, we will have to perform a procedure called re-crystallization, using ethyl acetate as our solvent instead of water in order to prevent decomposition of our products, and then once again we will use. Para-Aminosalicylic acid 4-hydroxybenzoic acid is used as an intermediate of bacteriostatic agent specially for p arabens alkyl esters of p-hydroxy benzoic acid which used in food and personal care products as a preservative.
He took salicylic acid and put the compound the many chemical reactions that would eliminate the acidic parts of the compound. Interpretation of results - comparison of retention factors -Has a smooth side and a rough side. Conducted aqueous FeCl3 test on both the salicylic acid control and the aspirin. The ice flask re-condenses most of the vapors, maintaining a nearly constant volume in the beaker throughout the experiment. Alkali and heat will decarboxylate both salicylic acid and sodium salicylate, the latter more readily even without alkali.
This experiment was carried out to see how the hydroxyl group on the benzene ring in salicylic acid reacts with acetic anhydride to form an ester, and to make aspirin. Sodium salicylate after evaporation of all the liquid at 65°C. It is one of the oldest and widely used drugs in medicine. Sodium Acetate and Pyridine were the basic catalysts in this experiment. Put some crushed ice and water into a 250-mL boiling flask and, using a clamp and support stand, place this on top of the beaker Fig.
A crust of salicylic acid may cling to the stirrer bar; this can be scraped off, or it can be heated to near boiling in 100 mL of water to dissolve the caking. The initial temperature was recorded using an alcohol thermometer. A small amount of deionized water was used to rinse the test tubes to ensure all solution is transferred to the flask. Some product was dissolved and lost in the washing process. How did this affect the end product? Paper covers all holes, but does not come up the sides -Pour crystals in solvent on top of the filter paper -Rubber stopper, clamp, connected to vacuum trap.
The initial melting point however was more than 10° lower than the literature melting point. The content was observed to measure the melting point range. Salicylic acid is more corrosive than acetylsalicylic acid. The expected amount of salicylic acid used: 21. Chemically, aspirin is both an aromatic acid and an ester; analgesic properties notwithstanding, the compound is an excellent showcase for at least two or three principles of organic chemistry. Para-Aminosalicylic acid and its sodium salt sodium p-Aminosalicylate are bacteriostatic against mycobacteria and used in the treatment of tuberculosis; administered orally. The product had a low percent yield and was found to be impure due to its low melting point.
Hydrolysis of acetylsalicylic acid is an equilibrium reaction catalyzed by acid as in this case or by base. The melting point, using the meltemp, was at 146º-158 º. Set up a 150 mL beaker with water to warm up on a hot plate medium heat 2. Aspirin is also effective in reducing fever, inflammation, and swelling and thus has been used for treatment of rheumatoid arthritis, rheumatic fever, and mild infection. Gloves are also a good idea.
The contents of all four test tubes were poured into the 125mL Erlenmeyer flask. The recorded mass was 23. It took 3 seconds for the temperature of test tube 3 to change by 4°C. Notice the magnetic stir bar in the bottom of the beaker. Suggested improvements include allowing the vacuum to run longer to absorb more of the water used in the filtration stage of the procedure. It is useful in the relief of headache and muscle and joint aches. Ethanol was used to dissolve aspirin along with the impurities such as salicylic acid and others.
Aqueous filtrates were diluted and flushed down the drain. On the other hand, water was added after heating not at the start of the experiment. One way to get the benefits of salicylic acid without its irritating characteristics is to add an acetyl group to it. In this experiment, acetic anhydride was used. Of the techniques to be used, heating under reflux is a common laboratory process to increase the rate of the reactions taking place in order to save time. A recommendation would be a more exact amount of reactants to be used.
Vacuum filter paper and a watch glass were obtained and their combined mass was recorded. In this experiment, there was an excess of water and more acetic anhydride was used due to the salicylic acid not being able to dissolve at the amount of 0. The objective, which is to create aspirin, has been completed due to the results shown by the data provided by an electronic instrument. Results and Discussion: Four test tubes and a test tube rack were obtained. Test tube 1 was placed back in the test tube rack. Small esters are actually fairly soluble in water but solubility falls with chain length and hydrophobic parts.