Synthesis and Purification Techniques, Aspirin, Tylenol, Caffeine, Lab Reports of Geochemistry

Download Synthesis and Purification Techniques, Aspirin, Tylenol, Caffeine and more Lab Reports Geochemistry in PDF only on Docsity! 1 Mehta Title: Synthesis and Purification Techniques, Aspirin, Tylenol, Caffeine Name(s): Veda Mehta (Bandarupalli, Sansster, Stone) Date experiment was performed: May 17, 2018 Aim: To synthesize acetaminophen from acetic anhydride, to synthesize aspirin, and to extract caffeine from tea. Experimental: Chemicals: Name Structure Physical Acetyl Salicylic acid (Aspirin) C9H8O4 Solid, mp = 135°C, MW = 180 g/mol Acetaminophen (Tylenol) C8H9NO2 Solid, MW = 151.17 g/mol, mp – 169°C Caffeine Solid, mp – 238°C, MW = 194.19 g/mol Salicylic acid Solid, mp = 159°C, MW = 138.1 g/mol p-aminophenol Solid, MW = 109.1 g/mol, bp = 284°C Acetic anhydride Liquid, d=1.08 g/mL, bp = 139.8°C, MW = 102.1°C Reagents: H3PO4, dichloromethane, p- Equipment: Filter Flask Hot Plate Hirsch Funnel Separatory Funnel Test Tube Clamp Vacuum Adapter Spatula 2 Mehta aminophenol, anhydr. MgSO4 Setup: Procedure: A literature 1 procedure was followed with the following modifications (and more that are not listed): a. Four drops of H3PO4 were used instead of five drops b. Sand bath was not used for Tylenol synthesis c. For Trial 1, 25mL of dichloromethane was used instead of 15mL. For Trial 2, 20mL of dichloromethane was used instead of 15mL d. 75mL of deionized water was poured in the caffeine extraction instead of 50mL Chemical reaction/mechanisms: Data: Tylenol Aspirin Caffeine Initial mass (g) 0.1496 0.5500 5.0344 Final mass (g) 0.0929 0.0255 0.0201 Results: Tylenol Aspirin Caffeine Moles of Reactant (mol) 0.0014 0.0031 0.0260 Moles of Product (mol) 0.00085 0.00014 0.00010 5 Mehta 2. In the reaction between p-aminophenol and acetic anhydride to form acetaminophen, some water was added. What was the purpose of the water? The water was added because it acts as a polar solvent which speeds up the reaction. The polar solvent helps assure that the products are dissolved and stable. 3. Why should you use a minimum amount of water to rinse the conical vial while transferring the purified acetaminophen to the Hirsch funnel? It is important because it assures that there is a minimum loss of product (loss by dissolving in the water) while filtering it in the funnel. 4. If 0.130 g of p-aminophenol is allowed to react with excess acetic anhydride, what is the theoretical yield of acetaminophen in moles? in grams? p-aminophenol + acetic anhydride  acetaminophen + acetic acid p-aminophenol = 0.130 g moles = 0.130 g/109 g/mol = 1.2E10-3 (1.2E10-3 moles p-aminophenol)( 1mol acetaminophen 1mol p−aminophenol ) = 1.2E10-3 mol acetaminophen Mass = (1.2E10-3 mol)(151 g/mol) = 0.181 grams 5. Give two reasons why the crude product in most reactions is not pure. One of the reasons why the crude product is not pure is because a small change in temperature can lead to an unwanted compound to form and mix into the product. Another reason is because sometimes the reaction is not 100% complete; this means that there could be some reactant left in the product. 6. Phenacetin has the structure shown. Write an equation for its preparation starting from 4- ethoxyaniline. The equation for the preparation of phenacetin starting from 4-ethoxyaniline is as follows: 6 Mehta 7. Give a complete balanced equation for the esterification reaction between the following pair. Draw the appropriate structure for each of the reactant and products. Give a scientific name for the ester formed. a. Benzoic acid and propanol +  Benzoic acid + propanol  propylbenzoate b. Pentanoic acid and ethanol +  Pentanoic acid + ethanol  ethylpentanoate c. Acetic acid and cyclopentanol +  Acetic acid + cyclopentanol  cyclopentylethanoate