Ester Synthesis Lab Report

In this part of experiment, alcohol(2ml) and CH3COOH(1ml) will react to produce an ester, the ester's odor can then be compared with that of the ester bank to determine the identity of the ester. This is done by mixing the reagents in the solution with a glass stirring rod and then to further dissolve the solution, it

Next, I noticed that my spectra showed a 2H, quintet, a CH2 at 1.6. Then, I noticed that my spectra showed a 3H, doublet, a CH3 at 1.3 and a 3H, triplet, a CH3, at 0.98. Lastly, I noticed that my spectra showed a 1H, sextet at 2.7 and I knew that it was a C-H bond because it gave me the correct amount of carbon’s and hydrogen’s. Since my spectra had a monosubstituted ring, I knew that that piece went on the end. I knew that my two methyl groups also went on the ends of the structure. Then for the C-H bond, I knew that that piece had to go in between to the monosubstituted ring and one of the methyl groups, which left the

If the IR spectra showed that it was an alcohol, Jones Test and Lucas Test can be used. If the IR spectra showed that it was either an aldehyde or ketone, we can use the DNP Test, Jones Test, and Tollens test, to determine which functional group is in the unknown. The IR Spectra can distinctively show the unknown as an alcohol, but cannot distinctively distinguish between aldehyde and ketone, because aldehyde and ketones have similar characteristic absorbances. Therefore, to distinguish between aldehyde and ketone, further chemical tests are needed. In the IR Spectra of unknown #305, it indicated that it was most likely an alcohol, due to the O-H peak at

The main purpose of this experiment was to synthesize an unknown ester using Fischer esterification reaction between an unknown carboxylic acid and an unknown alcohol as reactants as well as sulfuric acid as a catalyst. At the first step, the reaction mixture was created using the two key reactants, then the product was isolated by removing the aqueous layer. Through the distillation process, the crude product was purified to generate a clear liquid with a banana like odor as a final product of the reaction. The final product was a clear liquid with a banana like odor that usually comes from banana oil existed either in pure isoamyl acetate or pentyl acetate. The unknown ester was identified by using three common techniques IR, 13C NMR, and

In the first part of this experiment, an ester product will be isolated and purified from unknown alcohol. Then the product ester will be identified through analysis of boiling point, gas chromatography, and IR spectroscopy. In the second part of the experiment, Biodiesel will be synthesized from vegetable oil by transesterification.

To analyze the product and confirm its molecular identity, infrared spectroscopy and proton NMR spectroscopy were conducted. The H1NMR produced a spectra (Figure 5) which was consistent with the predicted chemical shift from the hypothesized product. The presence of a multiplet centered on the 7 ppm region is indicative of the presence of protons bound to a benzene ring as would be expected in the desired product. This region also likely had some overlap of the hydrogen bound to the sp2 Carbon that occurred as a result of the aldol dehydration step. Furthermore, the fact that all remaining proton signals lie in the sp3 up-field region validates the probable formation of the desired product as no other functionality is present to cause a

This data would indicate that the ester was converted into the targeted alcohol. In order to confirm this assumption H-NMR was employed. Since both compounds contain a benzene ring and at least one methyl group, the peaks around the 7ppm and 1.5ppm regions would not be enough to distinguish between the two compounds (6, 7). Instead the signals at 5.9ppm and 4.8ppm were looked at to distinguish between the two compounds. Since esters contain multiple electronegative oxygens the proton attached to the carbon adjacent to the ester experiences a greater magnetic field and thus a more downfield signal at 5.9ppm (6, 13), whereas the single oxygen of the alcohol induces a slightly weaker upfield signal at 4.8ppm (7, 13). Additionally, for the NMR spectra with the signal at 4.8ppm, there was a single short peak at 2.7ppm that is a unique signature to the presence of an alcohol (13). Lastly TLC chromatography was used while monitoring the progress of the lipase reaction. The ester is slightly less polar than the alcohol because the ester lacks the ability to be a hydrogen bond donor making it more nonpolar by comparison. As a result while monitoring TLC the ester had traveled further up the polar stationary phase, silica plate, while the alcohol traveled slower the plate (11). This same logic was applied to explain why it took the alcohol longer to elute from column

The purpose if this experiment is to prepare 5-cis- and 5-trans-3-(4-methylphenyl)-2-propenoic acid ethyl ester using formation of a stabilize ylide and p-tolualdehyde in a methanol solvent. The stabilize ylide is formed by a reaction of phosphonium salt, triphenylphosphonium bromide, and aqueous sodium hydroxide. The products made under reflux are separated using liquid-liquid extraction, and purified using rotary evaporator. The product was analyze using H-nuclear magnetic spectroscopy to determine the desired prepare 5-cis- and 5-trans-3-(4-methylphenyl)-2-propenoic acid ethyl ester formed with hexane by products. The percent yield was 72%.

Purpose: In this experiment, there are five known compounds given and one unknown compound. The known compounds are: aldehydes, ketones, primary and secondary alcohol, and ester. The Dumas method is used to determine what the unknown substance is. Both Aldehydes and Ketones are similar in a way that they both have carbonyl groups in their Lewis structure; the only difference between the two are that aldehydes are quickly oxidized into carboxylic acids whereas it more difficult to achieve.1 There are three different types of alcohols; there are primary, secondary and tertiary alcohols.

Esters are a specific type of functional group that can be derived from carboxylic acids. The –COOH group found within a carboxylic acid is changed to form an ester, specifically the hydrogen molecule, which is replaced by a hydrocarbon. Esters are present in many common things like animal and vegetable fats and oils. Made up of long, complex esters, the physical differences between fats and oils are in fact due to the different melting points of esters contained in each. For example, if the melting point of a substance is said to be below room temperature, the product will be a liquid and thus be classified as an oil. In contrast, if the melting point is said to be above room temperature, the product will be a solid and thus be classified as a fat. Esters can also be found in many perfumes or fragrances since they have a pleasant or fruity aroma. This unique smell is highly dependent on the structure of the molecule, meaning that even the slightest change can alter its scent. This is very important when considering how esters are formed. As stated previously, esters are derived from carboxylic acids, and thus need to be obtained through special reactions, like the Fischer Esterification reaction. Fischer esterification is the process of creating an ester from a carboxylic acid by heating it with an alcohol, while in the presence of a strong acid being used as the catalyst. This reaction needs to be monitored very closely to make sure the ester is formed correctly in order

The boiling points recorded for both compounds were slightly off due to an error while performing the lab. The thermometer was set too low to the vigrex column, resulting in lower boiling points. This can be fixed by raising the thermometer in the stillhead to height of where the glassware splits. Even with this discrepancy, the identity of both compounds was still confirmed. For fraction A, the IR RM-03-IRA was obtained. This spectrum contains a peak at 2877 cm-1 and a peak at 1106 cm-1. The second peak shows that the compound contains an ether. The presence of this functional group and the lack of a carbonyl group and hydroxyl group eliminated 9 of the 13 possible unknowns. The NMR spectra eliminated the other three possibilities. The NMR spectra obtained for fraction A are RM-03-NMRA1 and RM-03-NMRA2. The 1H NMR, RM-03-NMRA1, showed only 2 types of protons present, one represented at 3.47 ppm and the other at 3.32 ppm. It also showed that there was acetone in the NMR tube by the presence of the peak at 2.09 ppm. There were only two compounds left that had two types of protons, 1,2-dimethoxtethane and

The type of esterification that will be performed is esterification of carboxylic acids (called Fischer–Speier esterification)

The letters R in the reaction represent alkyl groups which are made up of carbon atom(s). An esters structure as shown contains a carbon atom double bonded to an oxygen atom, single bonded to an oxygen atom which is bonded to an alkyl group, and single bonded to another alkyl group as shown in the image (p.49 Nelson, 2010). The first portion of an esters name is derived

With this information, one can finalize the actual formation of the structure by signals provided. With the given 13C NMR we were allowed to determine the symmetry of the ring of our molecule. The spectra had five distinct signals. Signal 1 and 2 with a reading of 129.40 and 130.86ppm respectively were longer than the other signals. With this one assume that there are two of the same atom groups in signal 1 and 2 respectively. Which makes sense since after discovering that we were dealing with aromatic structure and in an aromatic structure there are 6 carbons but we only see 4 carbon in our spectra that are close together this gives evidence that both signal 1 and 2 are given off a signal for more one carbon in the same environment in the aromatic structure. In addition, signal 3 and 4 at 134.69 ppm and 140.84 respectively were further downfield than signal 1 and 2 because they were the closest carbons on the ring that were next to an electronegative atom. According to the 13C NMR chemical shift table the ppm values observed in signals 1-4 correlate to 150-120 for an aromatic structure which confirms with what was observed in the IR spectra. Signal 5 with the highest ppm reading at 190.80ppm refers to the functional group because it is the most downfield due to it being near an electronegative atom. Also, compared to the other signals

The purpose of this experiment is to observe the synthesis of esters (also known as esterification), to understand the chemical processes that ester synthesis undergoes, and to know the optimum conditions needed for high yields. Esterification is a Nucleophilic Acyl Substitution Reaction