The purpose of this experiment is to isolate and recrystallize trimyristin from nutmeg and then hydrolyze the trimyristin in a mixture containing 6M NaOH, 95% ethanol, and HCL to form myristic acid.
In a 250 mL round bottom flask, nutmeg (1.010 g, 2.29 mmol) and tert-butyl methyl ether (3 mL) were added and boiled for ten minutes. Once the solution had boiled and cooled, the liquid layer was filtered into a 25- mL Erlenmeyer flask via microscale filtration techniques. Tert-butyl methyl ether (2 mL, 22.69) was added to the round bottom flask, heated, and filtered again (percent recovery, 24.578- 24.107). After the second filtration, the 25- mL Erlenmeyer flask was warmed and air was blown over the solution until all of the solvent evaporated and the solid yellow product remained. The product was dried for five minutes and the crude weight was obtained (0.471 g, 0.65 mmol) and acetone (9.4 mL) was added and warmed until the solid dissolved. The solution was cooled to room temperature for 5 minutes and then cooled in an ice bath for 15 minutes. The solid product was filtered via suction filtration and washed with cold acetone. After filtration and drying the crystals were collected, weighed (0.189 g, 0.261 mmol) and the melting point range (49-51 °C) of the product was obtained.
A sample from the product (0.59 g, 0.816 mmol) was added to a new round boiling flask with 6 M NaOH (2 mL, 50 mmol) and 95% ethanol (2 mL, 43.41 mmol). The solution was brought to a boil and refluxed for 45 minutes. During this time, the remaining product (0.130 g, 0.18 mmol) was dissolved in boiling acetone (1 mL), cooled to room temperature for 10 minutes, cooled in an ice bath for 10 minutes and recrystallized a second time. The weight of the second recrystallization (.061 g, 0.084 mmol) and the melting point range (51-53°C) was observed. After the 45- minute hydrolysis, the flask was cooled to room temperature and the solution was poured into a 50 mL beaker containing water (8 mL, 444.44 mmol). HCl (2 mL, 65.38) was added dropwise to the beaker. The beaker was then cooled on ice for ten minutes with stirring and then filter via suction filtration. The product was dried overnight then the weight (0.077 g, 14.7%) and melting point (52-53 °C) were measured.
Crude trimyristin was extracted from nutmeg (1.010 g, 2.29 mmol) and recrystallized using acetone. Following the first recrystallization, majority of the sample underwent hydrolysis and acidification to form myristic acid. The remainder of the sample was recrystallized a second time. After the original extraction from nutmeg the crude trimyristin was recovered (0.471 g, 46.63%). This low yield makes sense because nutmeg is not composed solely of trimyristin. This trimyristin (0.471, 0.65 mmol) was then recrystallization and recovered (0.189 g, 18.71%). A low yield after recrystallization is common because impurities are ridden from the starting sample. However this very low percent recovery could be due to the left over crystals that remained in the flask after transfer to the suction filtration. Some crystals were also not able to be scraped off the side of the funnel from the suction filtration. The melting point of the trimyristin after the first recrystallization was 49-51°C. The true melting point of trimyristin is 56-57°C so the low recorded melting point range indicates the sample was not yet pure. A sample of the trimyristin product (0.130 g, 0.18) was recrystallized a second time (0.061 g, 46.92%). This percent yield makes sense because the sample had more impurities needed to be filtered out of the product. The melting point of the trimyristin after the second recrystallization was 51-53 °C. This increased melting point range indicated there were less impurities left in the product then the first because compounds melt at lower temperatures when they contain contaminants. However, even after the second recrystallization the sample is still not considered pure as it is still significantly lower than the true range of 56-57 °C. The main product of the trimyristin (0.059 g, 0.816 mmol) underwent hydrolysis and acidification to form the target product of myristic acid (0.077 g, 14.7%) The low percent yield is due to the loss of product during hydrolysis. The solution was too close to the heat source causing it to overheat and it went up the distillation column sticking to the sides. A rinse with 95% ethanol was done but not all of the product was removed from the insides of the column. The melting point range of this target sample was 52-53 °C. This melting point range confirmed the product identity because the melting point of myristic acid is actually 54.5 °C. The target product was not 100% pure because the measure melting point range was a few degrees lower than the true melting point range. However the accuracy of the thermometer is within 2 °C which allows the measured result to be a reliable confirmation that the final product was the targeted myristic acid.