Saponification Myristic Acid
Saponification and Acidification: From Nutmeg to Trimyrisitin to Sodium Myristate to Myrisitic Acid
Mandy Boyle
Chem 213, Section 002
Due Date: December 3, 2009
I. Introduction
People encounter esters everyday in both natural and synthesized forms. Esters are present in a variety of common compounds, from fragrances to animal fat (McMurry, 2008). Although these esters can undergo many different important reactions, this lab is particularly interested in the hydrolysis of esters into carboxylic acids and alcohols. Companies such as Dove, Palmolive, Dial, and many others owe their success to this specific reaction because the carboxylic acid produced in this reaction is soap. As such, this process is also commonly known as saponification …show more content…
(Reber, 2004).
A soap, such as sodium myristate, can be synthesized from a fat, such as Trimyristin, through the saponification reaction. The mechanism of ester hydrolysis (saponification), shown in Figure 1, initially proceeds through a simple nucleophilic addition of a hydroxide ion, which creates a tetrahedral intermediate. The carboxylic acid produced by elimination of an alkoxide ion from the intermediate is deprotonated by the same alkoxide ion. Thus, an intermediate carboxylate ion is also produced (McMurry, 2008). When in association with a sodium anion, this caboxylate ion unites with the anion to form the soap. Figure 1. Synthesis of Sodium Myristate by Nucleophilic Addition Reaction of Trimyristin with Base and Ethanol
Soap has important industrial functions as a cleaning agent, due to its unique structure and functional groups. The structure of a typical soap molecule is depicted in Figure 2. The carboxylate head of soap is ionic and thus hydrophilic, whereas the hydrocarbon tail of soap is non-polar and thus hydrophobic (Alberts, 2004). This distinctive structure allows for its’ ability to form clusters, around grease or dirt particles, collectively called a micelle, and remove them using water (Reber, 2004).
Figure 2. Soap Molecule
(Reber, 2004) Saponification is the primary method of making common crude soaps such as sodium myristate. The purpose of this experiment was to extract trimyristin from ground nutmeg through refluxing, to saponify trimyristin to sodium myristate, and to synthesize myristic acid from sodium myristate. Furthermore, the purpose was to isolate trimyristin through vacuum filtration, to purify trimyristin through recrystalization, and to analyze it through melting point determination and infrared spectroscopy (IR). The purpose was also to isolate sodium myristate through vacuum filtration, to analyze it through solubility tests, to isolate myrisitic acid through vacuum filtration, and to analyze it through proton nuclear magnetic resonance (1H NMR) and IR.
II. Experimental
Trimyristin. Ground nutmeg (20 g), diethyl ether (50mL), and a stir bar were added to a greased, 100mL round-bottom flask. The mixture was refluxed for 30 minutes, cooled, and decanted. The solid was isolated through vacuum filtration using a Buchner funnel, washed with ether (2 x 10mL), and dried overnight. The solid was then recrystalized using warm ethanol (95%, 15mL) and cooled. The solid was isolated through vacuum filtration, washed with chilled ethanol until white, and dried. The granular, white crystals where weighed (1.652g), melted (55-57°C), and analyzed through IR.
Table 1. IR Data: Trimyristin Run on the Solids IR Spectrometer Significant Signal(s) | Observed | Bond Stretch | 1732 cm-1 | C=O (ester) |
Sodium Myristate. Ethanol (95%, 20mL), NaOH pellets (.2g), trimyristin (1g), and a stir bar were added to a 100mL round-bottom flask and refluxed for 20 minutes. The mixture was cooled and water (20mL) and NaCL solution (20mL) were added. The solid was isolated through vacuum filtration, washed with cold water (25mL), dried, and weighed (.638g, 68%). The crystals were analyzed through solubility tests in which diluted sodium myristate (5mL) was added to three test tubes, one with corn oil, one with aqueous FeCl3 (1%, 10 drops), and one with aqueous CaCl2 (1%, 10 drops). The results were recorded into Table 2. | Corn Oil | 1% aq. FeCl3 | 1% aq. CaCl2 | Observations | homogenous solution formed | brown precipitate formed | white precipitate formed |
Myristic Acid. Sodium myristate (.5g) was added to distilled water (40mL) to create aqueous sodium myristate for the solubility tests. The remaining solution, about 25mL, was cooled over an ice bath. HCl was added dropwise, until the solution had a pH of 4, and a white solid precipitate formed. The solid was collected by vacuum filtration, washed with chilled water (10mL), dried, melted (53 – 59°C), and weighed (.362, 72%). The white crystals were analyzed with 1H NMR and IR.
Table 3. 1H NMR Data from Myristic Acid Dissolved in d-chloroform Significant Signals | Observed | Proton | 2.213ppm, multiplet* | R-CH3 | 0.879ppm, multiplet* | R2-CH2 |
*multiplet caused by overlap of similar protons
Table 4. IR Data: Myristic Acid on the Solids IR Spectrometer Significant Signals | Observed | Bond Stretch | 2914.2 cm-1 | C=O (from carboxylic acid) | 1693.6 cm-1 | O-H (from carboxylic acid) |
III. Results and Discussion Many results indicated a successful synthesis of the products/intermediates during the multi-step experiment. First, the high percent yield indicates a successful reaction. The trimyristin saponification resulted in a 68% yield and the myristic acid synthesis resulted in a 72% yield. Since the experiment was preformed in multiple steps, and each step required a transfer into a different container, the small amount of loss in each case may have been from the inability to retrieve the entire product from each container. A high yield indicates an effective experiment with little procedural error.
The IR analyses (attached to the end of the report) indicate a successful isolation of trimyristin and synthesis of myristic acid.
The trimyristin IR shows a stretch at 1732.4 cm-1, which is concurrent with the expectations due to the ester present in trimyristin’s structure. This indicates that trimyristin was successfully extracted from nutmeg. The myristic acid IR shows stretches at 2914.2 cm-1 and 1693.6 cm-1. Since sodium myristate has the same structure as myrisitic acid aside from the proton of the carboxylic acid, the O-H bond stretch is the most significant factor in determining if the myristic acid was indeed synthesized. Thus, the 2914.2 cm-1 bond stretch indicates a successful synthesis of myristic …show more content…
acid.
The qualitative tests preformed with corn oil, aqueous FeCl3, and aqueous CaCl2 indicate a successful saponification reaction.
Soap is somewhat miscible in both fat and water, so adding soap to corn oil would be expected to produce emulsions. Emulsions within a homogenous solution were in fact produced, suggesting that sodium myristate was successfully synthesized. Adding soap to aqueous FeCl3 or aqueous CaCl2 would cause the ions to exchange and create iron or calsium myristate, the insoluble brown and white precipitates formed during the second and third qualitative tests (Noller, 1953). These preciptates therefore suggest that sodium myristate was successfully synthesized. The myristic acid NMR analysis (attached to the end of the report) also indicates a successful synthesis. Aside from the acetone and DCM impurities, the myristic acid NMR shows hydrocarbon peaks at 2.213ppm and .879ppm. These peaks coupled with the fact that sodium myristate would not dissolve in the organic dichloromethane solvent indicates that the reaction resulted in the synthesis of myristic acid. Unfortunately, the high volume of the impurities throws off the integration values of the peaks, so the integration values given cannot be used to indicate the identity of the
compound. Therefore, the trimyristin IR suggests a successful trimyristin isolation, the qualitative tests suggest a successful sodium myristate synthesis, and the myrisitic acid IR and NMR suggest a successful myristic acid synthesis. Further experiment could also include qualitative tests of the solubility of the final product. These tests would add to the identification of the final product as myristic acid because sodium myristate and myristic acid have different solubility properties (as one is an acid and one is an organic salt). Overall, the experiment can be considered a success.
IV. References
Alberts; Bray; Hopkin; Johnson; Lewis; Raff; Roberts; Walter. Essential Cell Biology,
2nd edition. 2004: Garland Science, pp. 53-54.
McMurry, John. Organic Chemistry, seventh edition. 2008: Thomson Brooks/Cole, pp. 809-810, 1064.
Noller, C.R. Textbook of Organic Chemistry; W.B. Saunders Co: Philadelphia, 1953. pp. 157-158 “Product Name or No.” 2009. Sigma Aldrich. 14 Sept. 2009
<http://www.sigmaaldrich.com>.
Reber, K. Soap from Nutmeg.
Mandy Boyle
Chem 213, Section 002
Due Date: December 3, 2009
I. Introduction
People encounter esters everyday in both natural and synthesized forms. Esters are present in a variety of common compounds, from fragrances to animal fat (McMurry, 2008). Although these esters can undergo many different important reactions, this lab is particularly interested in the hydrolysis of esters into carboxylic acids and alcohols. Companies such as Dove, Palmolive, Dial, and many others owe their success to this specific reaction because the carboxylic acid produced in this reaction is soap. As such, this process is also commonly known as saponification …show more content…
(Reber, 2004).
A soap, such as sodium myristate, can be synthesized from a fat, such as Trimyristin, through the saponification reaction. The mechanism of ester hydrolysis (saponification), shown in Figure 1, initially proceeds through a simple nucleophilic addition of a hydroxide ion, which creates a tetrahedral intermediate. The carboxylic acid produced by elimination of an alkoxide ion from the intermediate is deprotonated by the same alkoxide ion. Thus, an intermediate carboxylate ion is also produced (McMurry, 2008). When in association with a sodium anion, this caboxylate ion unites with the anion to form the soap. Figure 1. Synthesis of Sodium Myristate by Nucleophilic Addition Reaction of Trimyristin with Base and Ethanol
Soap has important industrial functions as a cleaning agent, due to its unique structure and functional groups. The structure of a typical soap molecule is depicted in Figure 2. The carboxylate head of soap is ionic and thus hydrophilic, whereas the hydrocarbon tail of soap is non-polar and thus hydrophobic (Alberts, 2004). This distinctive structure allows for its’ ability to form clusters, around grease or dirt particles, collectively called a micelle, and remove them using water (Reber, 2004).
Figure 2. Soap Molecule
(Reber, 2004) Saponification is the primary method of making common crude soaps such as sodium myristate. The purpose of this experiment was to extract trimyristin from ground nutmeg through refluxing, to saponify trimyristin to sodium myristate, and to synthesize myristic acid from sodium myristate. Furthermore, the purpose was to isolate trimyristin through vacuum filtration, to purify trimyristin through recrystalization, and to analyze it through melting point determination and infrared spectroscopy (IR). The purpose was also to isolate sodium myristate through vacuum filtration, to analyze it through solubility tests, to isolate myrisitic acid through vacuum filtration, and to analyze it through proton nuclear magnetic resonance (1H NMR) and IR.
II. Experimental
Trimyristin. Ground nutmeg (20 g), diethyl ether (50mL), and a stir bar were added to a greased, 100mL round-bottom flask. The mixture was refluxed for 30 minutes, cooled, and decanted. The solid was isolated through vacuum filtration using a Buchner funnel, washed with ether (2 x 10mL), and dried overnight. The solid was then recrystalized using warm ethanol (95%, 15mL) and cooled. The solid was isolated through vacuum filtration, washed with chilled ethanol until white, and dried. The granular, white crystals where weighed (1.652g), melted (55-57°C), and analyzed through IR.
Table 1. IR Data: Trimyristin Run on the Solids IR Spectrometer Significant Signal(s) | Observed | Bond Stretch | 1732 cm-1 | C=O (ester) |
Sodium Myristate. Ethanol (95%, 20mL), NaOH pellets (.2g), trimyristin (1g), and a stir bar were added to a 100mL round-bottom flask and refluxed for 20 minutes. The mixture was cooled and water (20mL) and NaCL solution (20mL) were added. The solid was isolated through vacuum filtration, washed with cold water (25mL), dried, and weighed (.638g, 68%). The crystals were analyzed through solubility tests in which diluted sodium myristate (5mL) was added to three test tubes, one with corn oil, one with aqueous FeCl3 (1%, 10 drops), and one with aqueous CaCl2 (1%, 10 drops). The results were recorded into Table 2. | Corn Oil | 1% aq. FeCl3 | 1% aq. CaCl2 | Observations | homogenous solution formed | brown precipitate formed | white precipitate formed |
Myristic Acid. Sodium myristate (.5g) was added to distilled water (40mL) to create aqueous sodium myristate for the solubility tests. The remaining solution, about 25mL, was cooled over an ice bath. HCl was added dropwise, until the solution had a pH of 4, and a white solid precipitate formed. The solid was collected by vacuum filtration, washed with chilled water (10mL), dried, melted (53 – 59°C), and weighed (.362, 72%). The white crystals were analyzed with 1H NMR and IR.
Table 3. 1H NMR Data from Myristic Acid Dissolved in d-chloroform Significant Signals | Observed | Proton | 2.213ppm, multiplet* | R-CH3 | 0.879ppm, multiplet* | R2-CH2 |
*multiplet caused by overlap of similar protons
Table 4. IR Data: Myristic Acid on the Solids IR Spectrometer Significant Signals | Observed | Bond Stretch | 2914.2 cm-1 | C=O (from carboxylic acid) | 1693.6 cm-1 | O-H (from carboxylic acid) |
III. Results and Discussion Many results indicated a successful synthesis of the products/intermediates during the multi-step experiment. First, the high percent yield indicates a successful reaction. The trimyristin saponification resulted in a 68% yield and the myristic acid synthesis resulted in a 72% yield. Since the experiment was preformed in multiple steps, and each step required a transfer into a different container, the small amount of loss in each case may have been from the inability to retrieve the entire product from each container. A high yield indicates an effective experiment with little procedural error.
The IR analyses (attached to the end of the report) indicate a successful isolation of trimyristin and synthesis of myristic acid.
The trimyristin IR shows a stretch at 1732.4 cm-1, which is concurrent with the expectations due to the ester present in trimyristin’s structure. This indicates that trimyristin was successfully extracted from nutmeg. The myristic acid IR shows stretches at 2914.2 cm-1 and 1693.6 cm-1. Since sodium myristate has the same structure as myrisitic acid aside from the proton of the carboxylic acid, the O-H bond stretch is the most significant factor in determining if the myristic acid was indeed synthesized. Thus, the 2914.2 cm-1 bond stretch indicates a successful synthesis of myristic …show more content…
acid.
The qualitative tests preformed with corn oil, aqueous FeCl3, and aqueous CaCl2 indicate a successful saponification reaction.
Soap is somewhat miscible in both fat and water, so adding soap to corn oil would be expected to produce emulsions. Emulsions within a homogenous solution were in fact produced, suggesting that sodium myristate was successfully synthesized. Adding soap to aqueous FeCl3 or aqueous CaCl2 would cause the ions to exchange and create iron or calsium myristate, the insoluble brown and white precipitates formed during the second and third qualitative tests (Noller, 1953). These preciptates therefore suggest that sodium myristate was successfully synthesized. The myristic acid NMR analysis (attached to the end of the report) also indicates a successful synthesis. Aside from the acetone and DCM impurities, the myristic acid NMR shows hydrocarbon peaks at 2.213ppm and .879ppm. These peaks coupled with the fact that sodium myristate would not dissolve in the organic dichloromethane solvent indicates that the reaction resulted in the synthesis of myristic acid. Unfortunately, the high volume of the impurities throws off the integration values of the peaks, so the integration values given cannot be used to indicate the identity of the
compound. Therefore, the trimyristin IR suggests a successful trimyristin isolation, the qualitative tests suggest a successful sodium myristate synthesis, and the myrisitic acid IR and NMR suggest a successful myristic acid synthesis. Further experiment could also include qualitative tests of the solubility of the final product. These tests would add to the identification of the final product as myristic acid because sodium myristate and myristic acid have different solubility properties (as one is an acid and one is an organic salt). Overall, the experiment can be considered a success.
IV. References
Alberts; Bray; Hopkin; Johnson; Lewis; Raff; Roberts; Walter. Essential Cell Biology,
2nd edition. 2004: Garland Science, pp. 53-54.
McMurry, John. Organic Chemistry, seventh edition. 2008: Thomson Brooks/Cole, pp. 809-810, 1064.
Noller, C.R. Textbook of Organic Chemistry; W.B. Saunders Co: Philadelphia, 1953. pp. 157-158 “Product Name or No.” 2009. Sigma Aldrich. 14 Sept. 2009
<http://www.sigmaaldrich.com>.
Reber, K. Soap from Nutmeg.