Experiment 5

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Feb 20, 2024

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Experiment 5: Isolation of Trimyristin from Nutmeg and Preparation of Myristic Acid from Trimyristin by Hydrolysis and Preparation of Myristic Acid from Trimyristin by Hydrolysis Chase Morris 3/3/2023 CHM2210L-29 Heng Liu

Introduction: The isolation of an organic compound entails separating the a compound from other compounds in a mixture. There are various different ways to isolate an organic compound such as extraction, distillation, chromatography and crystallization. In this lab we will perform a hydrolysis of esters which can be done through acid-catalyzed and base-catalyzed hydrolysis, in this experiment base-catalyzed will be performed. Hydrolysis is the process of cleaving an ester bond by the addition of water, and in the presence of an acid or base the esters can be hydrolyzed to produce a carboxylic acid and an alcohol. In base-catalyzed hydrolysis the ester is reacted with a strong base, the strong base deprotonates the water molecule making it nucleophilic and able to attack the ester. The mixed melting point concept is the same as the melting point constant, it is used to test the purity of a compound, if the melting point of a compound is lower than expected it is due to an impurity of the compound. The mechanism used to hydrolyze myristic acid from trimyristin is a four step process. First the base-catalyzed hydrolysis will produce myristic acid and glycerol, then the solution is neutralized to counter the byproduct from the base-catalyzed hydrolysis. After it is neutralized myristic acid can be extracted from the solution by separating the layers and then drying the myristic acid. Finally the myristic acid needs to purified by recrystallization. There are different ways that an unwanted byproduct can be formed during this reaction whether it be saponification, acid-catalyzed dehydration, and isomerization.

Procedure: A 50mL Erlenmyer Flask 2g ground nutmeg 20mL diethel ether mix 20 mins Pasteur Pipet 2mm sand 1cm anhydrous sodium sulfate Place over 25mL vacuum flask with rubber septum clamp New Pipet Transfer content form erlenmyer flask Let flow through to vacuum flask Rinse packing material with .5 ml ether 25mL vacuum flask Cool in ice bath Dissolve with 1mL acetone over steam bath Hirsh Funnel Wet filter paper and rince with acetone Transfer solid sample to preweighted vial

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B Chemicals Used: Trimyristin o Physical Properties  Melting point: 56-57  c  Boiling point: 311  c  Molar mass: 723.16 g/mol o Chemical Properties  Chemical formula: C45H86O6 5mL Vial 200mg trimyristin 2mL ethanol 2mL 10% NaOH Boiling stones Run for 1 hour 50mL beaker Cold 10mL HCl Add mixture from vial check pH Dilute with 5mL cold water Vacuum filtrate Save crude Test tube 5mL petroleum ether Crude mixture Filter pipet 1in celite Myristic acid solution Gently force through with bulb Test tube Filtered myristic acid solution Evaporate solvent using steam bath Cool

 IUPAC name: 2,3-di(tetradecanoyloxy)propyltetradecanoate  Diethyl ether o Physical Properties  Melting point: -116.3  c  Boiling point: 34.6  c  Molar mass: 74.12 g/mol o Chemical Properties  Chemical formula: (C2H5)2O  IUPAC name: ethoxyethane  Anhydrous sodium sulfate o Physical properties  Melting point: 1429  c  Boiling point: 884  c  Molar mass: 142.04 g/mol o Chemical Properties  Chemical formula: Na2SO4  IUPAC name: Disodium sulfate  Myristic Acid o Physical Properties  Melting point: 54-55  c  Boiling point: 326.2  c  Molar mass: 228.37 g/mol o Chemical Properties

 Chemical formula: CH3(CH2)12COOH  IUPAC name: tetradecanoic acid  HCl o Physical Properties  Melting point: -114.2  c  Boiling point: -85.05  c  Molar mass: 36.45 g/mol o Chemical Properties  Chemical formula: HCl  IUPAC name: hydrogen chloride Results: Compound Mass (g) Melting Point (  c) Percent Yield Nutmeg 2.0g N/A N/A Crude Trimyristin .411g 44  c 20.6% Pure Trimyristin .2g 50-52  c 48.7% Crude Myristic Acid N/A 52.4  c N/A

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Pure Myristic Acid .1g 54.1  c 50% 1:1 Crude myristic acid & pure myristic acid N/A 46.8  c N/A % yield = Final mass (g) / Initial mass (g) x100% .2 trimyristin x 1 mol 723.16 g x 3 mol 1 moltrimyristin x 228.37 gmyristic acid 1 mol = .1894 g Discussion: None of the yields from this experiment were high unfortunately. The crude trimyristin only had a yield of 20.6% or .411g from 2g of nutmeg and further from that only .2g or 48.7% of the trimyristin was able to be purified from the crude. However, from the .2g of pure trimyristin .1g of pure myristic acid was able to be obtained which is 50% yield, there will always be some lost during the process of purification and during transfers of the products I was hoping for a higher yield. The crude trimyristin had a melting point of 44  c while the expected is 56-57  c this is much lower and shows that the crude mixture was not pure. While the pure trimyristin was much closer to the expected at 50-52  c it was still 4  c lower than expected which indicated the presence of more impurities. Once the trimyristin was reacted to myristic acid the crude was measured at 52.4  c which is once again closer to the expect value, however, this could be because some pure trimyristin was used to get .2g to complete the experiment (.04g were used). After purification the myristic acid had a melting point of 54.1  c which is only 1.9  c from expected showing still some impurities but much purified than the crude. Finally, the 1:1

mixture of crude and pure myristic acid had a very low melting point of 46.8  c which shows that there were more impurities. Conclusion: The theories of this experiment outlined and illustrated the chemical reactions that occur in this experiment and how the process works step by step. This helped in the understanding of what happens and why it is happening and knowing that each step has a purpose. The data in this lab revealed a successful purification of myristic acid and trimyristin, this was verified through the melting point tests, I would have liked the results to be closer to the expected however the consistent improvement of the melting point showed the continued purification of the myristic acid and trimyristin. Hydrolysis is a hugely important chemical reaction that occurs everywhere and is especially important in your body making the process and practice of the process very interesting and provided a lot of insight into some cellular processes. Yes, this lab accomplished exactly what was set out, myristic acid was purified from a hydrolysis reaction of trimyristin. References: Weldegirma, S. Experimental Organic Chemistry , 11th ed.; Pro-Copy: Tampa, FL, 2023. Hydrochloric acid. https://pubchem.ncbi.nlm.nih.gov/compound/Hydrochloric-Acid (accessed Mar 3, 2023). Myristic acid. https://pubchem.ncbi.nlm.nih.gov/compound/Myristic-acid (accessed Mar 3, 2023). Trimyristin. https://pubchem.ncbi.nlm.nih.gov/compound/Trimyristin (accessed Mar 3, 2023).

Diethyl ether. https://pubchem.ncbi.nlm.nih.gov/compound/Diethyl-Ether#:~:text=Diethyl %20ether%20is%20an%20ether,organic%20compound%20and%20an%20ether. (accessed Mar 3, 2023). Sodium sulfate. https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-sulfate (accessed Mar 3, 2023).

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