The percent yield for the reaction was rather low, 48.02%. This could be a result of a possible loss of product during the washing phase when releasing the gas. The loss of product could have occurred when trying to pipet the dried ester. The boiling point for the product was not taken. The H-NMR of the unknown alcohol was provided for analysis in order to determine the identity. Based on the peaks and their respective locations, the unknown was determined to be isopentanol. The peak at 0 ppm was the TMS. From this, the first doublet peak represented the six hydrogens located on the two terminal carbons, the signal was split as a result of the single hydrogen from the adjacent carbon. This peaks falls within the typical range for a primary alkyl hydrogen, 0.7-1.3 ppm. The next peak is a quartet that has a …show more content…
For the acetic acid spectrum, the broad peak ranging from 3300 cm-1 indicate the presence of a carboxylic O-H bond. The little bump at just under 3000 cm-1 indicates the presence of sp3 carbon hydrogen bonds. The peak at 1704.3 cm-1 shows the presence of a carbon oxygen double bond. For the isopentanol spectrum, the peaks located just under 3000 cm-1 indicate carbon hydrogen bonds. The broad peak ranging from 3300 cm-1 to 3200 cm-1 indicate the presence of an oxygen hydrogen alcohol bond present. For the product, the peaks located just under 3000 cm-1 indicate carbon hydrogen bonds. The peak located at 1739.58 cm-1 indicate the presence of a carbon oxygen double bond, more specifically an ester carbon oxygen double bond, because it falls in the typical range of 1735 cm-1 to 1750 cm-1. In this spectra however, there is no peak located in the region for an alcohol O-H bond or a carboxylic acid O-H bond. Based on these spectra, the data indicates that the that the esterification has occurred
The objective of this lab was to create a ketone through an oxidation reaction using a using a secondary alcohol and oxidizing agent in order to use that ketone in a reduction reaction with a specific reducing agent to determine the affect of that reducing agent on the diastereoselectivity of the product. In the first part of this experiment, 4-tert-butylcyclohexanol was reacted with NaOCl, an oxidizing agent, and acetic acid to form 4-tert-butylcyclohexanone. In the second part of this experiment, 4-tert-butylcyclohexanone was reacted with a reducing agent, either NaBH4 in EtOH or Al(OiPr)3 in iPrOH, to form the product 4-tert-butylcyclohexanol. 1H NMR spectroscopy was used to determine the cis:trans ratio of the OH relative to the tert-butyl group in the product formed from the reduction reaction with each reducing agent. Thin-layer chromatography was used in both the oxidation and reduction steps to ensure that each reaction ran to completion.
The GC data for the product produced graph with a signal level out-of-range in peak. This gave a retention time 2.952 minutes. This would not indicate any of the possible ester products. However, after appropriate dilution, a retention time of 1.753 minutes was obtained. This retention time indicates that the ester product was ethyl benzoate.
This reaction is spontaneous for almost all esters but can be very slow under typical conditions of temperature and pressure. The reaction occurs at a much faster rate if there is a significant amount of base (OH-) in the solution. In this lab experiment, the rate of this reaction will be studied using an ester called para-nitrophenyl acetate (PNA), which produces an alcohol,
The range determined in the experiment is approximately 2 degrees above the actual melting point range, indicating some impurities in the final compound. According to the IR spectrum, the product obtained is quite pure. The peaks in the table above indicate the presence of a carbonyl, specifically the C=O bond of a cyclic ketone and also the sp2-hybridized =C–H bond of an alkene. There is no broad peak ranging from 3200 cm-1-3600 cm-1, which would indicate the presence of the -OH group of an alcohol. Thus, there is likely no presence of starting material in the final product. The percent yield above 100% indicates that some liquid (hexanes) used to recrystallize the product was likely still in the flask when the product was weighed.
The purpose of this experiment was to synthesize isopentyl acetate via an esterification reaction between acetic acid and isopentyl alcohol, using concentrated sulfuric acid as a catalyst. The product was washed with sodium hydrogen carbonate, as well as with water, then dried with anhydrous sodium sulfate. The product was then distilled using a Hickman still and characterized using infrared spectroscopy. The percent yield of isopentyl acetate was 61.52%. This may have been low due to not all of the condensed product being removed from the Hickman still, some product being lost during transfer of the product from the reaction tube into the Hickman still, or the loss of some product due to evaporation during distillation.
In this experiment, the main objective was to synthesize a ketone from borneol via an oxidation reaction and secondly, to produce a secondary alcohol from camphor via a reduction reaction. Therefore, the hypothesis of this lab is that camphor will be produced in the oxidation reaction and isoborneol will be the product of the reduction reaction because of steric hindrance. For the oxidation step, a reflux will be done and then a microscale reflux for the reduction step. The products will be confirmed using Infrared spectroscopy, the chromic acid test, 2,4-DNP test and 13C NMR spectroscopy. The results of this
Using the mole ratio it was calculated that the theoretical yield of ester was a mass of 19 g, equivalent to a 100% yield. Observation of the specific boiling points of the volatile components allowed the 56.83% yield of 11 grams of ester to be obtained after its evaporation at 122-124°C. The limited yield suggested poor experimental design with impacting the equilibrium reaction with possible insufficient heating, or only partial conversion of reactants into products impacting the yield. Thus, it can be seen that the Esterification reaction is a fairly unproductive in the context of our setting, thus making it expensive for industrial use unless modifications are implemented to improve
These signals confirm that ester product is indeed 2-pentyl acetate. Since 2-pentyl acetate was confirmed to be the synthesized ester, the starting alcohol must be
Synthesize isopentyl acetate by combining isopentyl alcohol with acetic acid and sulfuric acid and then heating the reaction mixture under reflux for an hour. The alcohol is the limiting reactant, so it should be weighed/ the acids can be measured by volume. The esterification reaction is reversible, and it has an equilibrium constant of approximately 4.2. A pure component can be obtained from a mixture by
Groups that contained oxygen were carbonyl (C=O) and alcohol (C-OH) with each bonding present for a different activity based on the location and also with a hybridization of C-O bond. The presence of carbonyl (C=O) did appear in treated glycerol at 1645.6200 cm-1 but not in commercial glycerol. This is caused by some impurities during product oxidation of glycerol for example glyceraldehydes, dihydroxyacetone and also free fatty acids (Yong et al., 2001). The alcohol group (C-OH) also appears in treated and commercial glycerol at a spectra value of 1015.2800 cm-1 and 1038.5400
Purpose: The purpose of the experiment was to perform the acid-catalyzed Fischer Esterification of acetic acid and isopentyl alcohol to form isopentyl acetate, or banana oil, which is used in flavor industries. The equilibrium of the reaction was changed by adding an excess amount of acetic acid. The reaction was refluxed and product was purified by extraction and distillation. Isopentyl acetate was analyzed by infrared spectroscopy and 1H NMR spectroscopy.
In this experiment, a Fischer Esterification reaction was performed with two unknown compounds. The unknown compounds, Acid 2 and Alcohol D, were identified by using the knowledge of the reaction that took place, and the identity of the product that was synthesized. The identification of the product resulted from analysis of IR and NMR spectra.
In the monohydric alcohol group there is Methanol (wood alcohol), ethanol (alcohol), isopropyl alcohol (rubbing alcohol), Butyl alcohol (butanol), pentanol (amyl alcohol), and hexadecan-1-ol (cetyl alcohol). Another group of alcohols would be the polyhydric alcohols. With these alcohols there are ethane 1,2-diol (ethylene glycol), propane 1,2-diol (propylene glycol), Propane-1,2,3-triol (glycerol), Butane-1,2,3,4-tetraol (Erythritol, Threitol), Pentane-1,2,3,4,5-pentol (xylitol), Hexane-1,2,3,4,5,6-hexol (Mannitol, Sorbitol), Heptane-1,2,3,4,5,6,7-heptol (volemitol). Another group of alcohols would be the unsaturated aliphatic alcohols. In this group would be Prop-2-ene-1-ol (allyl alcohol), 3, 7-Dimethylocta-2, 6-dien-1-ol (geraniol), and Prop-2-in-1-ol (Propargyl alcohol). The last group of the alcohols would be alicyclic alcohols. In this group there is Cyclohexane-1, 2, 3, 4, 5, 6-hexol (inositol) and 2 - (2-propyl)-5-methyl-cyclohexane-1-ol (menthol) (Britannica). The names above are just a list of some of the alcohols that can be found within the big range and different types of alcohols. The alcohols above use the same formats as alkanes to be named.
The results from the NMR of 1-propanol showed 3 different prominent peaks with the peak at 2.2 cm-1 being the acetone. Because 1-bromopropane has three non-equivalent hydrogens it was found to represent this set of NMR data. The other product, 2-bromopropane only had 2 different types of hydrogens and would have only had 2 peaks. Further analysis of the structure of 1-bromopropane showed that the hydrogens closest the bromine group were an indication of peak A in the graph. Because of the electronegativity of the bromine, this peak was located further downfield. There were 2 neighboring hydrogens so using the n+1 rule gave the 3 peaks. Going down peak B showed the next carbon which had 5 neighboring hydrogens thus giving 6 peaks. Finally, the carbon furthest away from the bromine was found at peak C. It had 2 neighboring hydrogens and provided 3 peaks.
A vibration can result in an absorption peak of infrared radiation, only if there is a change in the dipole moment of the molecule. The larger this change, the more intense will be the absorption band. Furthermore, the electron polarity vectors in the covalent bond should not cancel out i.e the covalent bonds must be asymmetric.