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Racemic Mixtures Lab Report

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With the isolation of (-)-1-phenylethamine a racemic mixture of 1-phenylethanamine was obtained. Utilizing hot plates 1-phenylethanamine was warmed up with Methanol and Tartaric acid to achieve recrystallization. Once the extraction of the crystals was complete they were put into a short path distillation method a pure 1-phenylethanamine was isolated. Ultimately, the experimental result calculations concluded with (47.8% S) and (52.2% R) optical purity. In addition, the overall calculated yield was 78.22%. Introduction: A racemic mixture has an equal mixture of (+) an (-) enantiomers. Enantiomers are defined as stereoisomers that have non-superimposable mirror images, and share the same physical properties-such as boiling points, melting points, IR, and NMR. Even though enantiomers have identical physical properties, an ability to rotate plane-polarized light happens in opposite directions often making it difficult to separate enantiomers (1). …show more content…

Treatment of a racemic mixture with tartaric acid which is an optically pure resolving agent helped in the separation of the racemic mixture into the R and S diastereomer salts because of their unique solubilities with methanol (2). It was evident that both diastereomers had different solubilites in methanol because one diastereomer R-(+)-amine dissolved in the solution while the other, S-(-)-amine precipitated into crystals and did not dissolve. The crystals were purified and further isolated through a vacuum filtration (1). Below, shows the treatment of a racemic mixture with tartaric acid and methanol. As mentioned before, the resulting product is diastereomeric salts, which were separated based on solubility

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