This week’s lab was an esterification reaction and the goals were to determine the unknown alcohol used for the reaction as well as the ester product. Esters appear in nature and are often an important component of many substances used in the flavor and fragrance industry. The ester made in this reaction was pentyl butanoate, which was made from butyric acid and an unknown acid. Pentyl butanoate is typically found in fruits such as apples, bananas, and apricot fruits. Some of the commercial uses of pentyl butanoate include food flavoring and an additive in cigarettes. The formation of an ester from an alcohol and a carboxylic acid can be catalyzed by strong acids such as sulfuric or anhydrous hydrogen chloride and is a reversible process. …show more content…
The product was not pure, which can be seen on the H NMR spectra of the product, containing impurities that resulted in the integrations to be slightly off. On the H NMR spectrum, it appears that the H’s farther away from the carbonyl and ester have the impurities since those are the slightly off integrations. Moreover, the splitting patterns for these H’s show some irregularities, which may be due to the impurities. Although the some integrations are inconsistent with the predicted product, when adjusted to account for impurities, the spectrum does confirm the isolation of an ester with the number of H’s (18 H’s) and constitutionally inequivalent H’s (5 H’s) matching. On the other hand, the identification of the unknown alcohol, found to be 1-pentanol, was easier in the respect that the H NMR was not contaminated. The H NMR showed 12 H’s and 5 constitutionally inequivalent H’s with 6 of the H’s having quartets in the ppm range of alkanes, as well as having a H in the ppm range of a C-OH. In addition to the IR spectrum, which showed an OH stretch at 3328.20 cm-1, a CH stretch for alkanes around 2850-2930 cm-1, and a CO stretch for alcohols at 1053.75 cm-1, the proposed alcohol of 1-pentanol could be confirmed to be the unknown alcohol. In order of discovery, the unknown alcohol was first found in order to predict the product of the
After 10 minutes the reaction liquid was separated from the solid using a vacuum filtration system and toluene. The product was stored and dried until week 2 of the experiment. The product was weighed to be 0.31 g. Percent yield was calculated to be 38.75%. IR spectra data was conducted for the two starting materials and of the product. Melting point determination was performed on the product and proton NMR spectrum was given. The IR spectrum revealed peaks at 1720 cm-1, which indicated the presence of a lactone group, and 1730 cm-1, representing a functional group of a carboxylic acid (C=O), and 3300cm-1, indicating the presence of an alcohol group (O-H). All three peaks correspond with the desired product. A second TLC using the same mobile and stationary phase as the first was performed and revealed Rf Values of 0.17 and 0.43for the product. The first value was unique to the product indicating that the Diels-Alder reaction was successful. The other Rf value of 0.43 matched that of maleic anhydride indicating some
reaction. The purpose was to learn what a SN1 reaction was with combining 2,5-dimethyl-2,5-hexanediol and HCl and to learn how to use an infrared spectrum for analyzing the reaction. The infrared spectrum determined the alcohol content
In this experiment, the Fischer Esterification of an unknown acid and an unknown alcohol was used to prepare an unknown ester. Sulfuric acid was used as a catalyst in the reaction which then was put under reflux. After cooling, the pH of the solution was raised to approximately 8 using sodium carbonate. Diethyl ether was added, then the aqueous layer was removed and the organic layer was washed with sodium chloride. The aqueous layer was removed again and sodium sulfate was added. The unknown product was then identified using gas chromatography (GC) to obtain the retention time.
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.
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
The hypothesis tested in this experiment was, if the temperature of enzyme catalysis were increased, then the reaction rate would increase, because enzyme-catalysis reacts by randomly colliding with substrate molecules, and the increase in temperature increases the speed of collision or reaction rate. The final data collected for the experiment was positive with my hypothesis. The coffee filter, covered in potato solution, sank and rose at a faster pace in the hydrogen peroxide when the temperatures were raised.
An ester was synthesized during an organic reaction and identified by IR spectroscopy and boiling point. Acetic acid was added to 4-methyl-2-pentanol, which was catalyzed by sulfuric acid. This produced the desired ester and water. After the ester was isolated a percent yield of 55.1% was calculated from the 0.872 g of ester recovered. This quantitative error was most likely due to product getting stuck in the apparatus. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. The values of the
The dehydration of 2-methyl-2-butanol was performed using sulfuric acid and phosphoric acid in order to synthesize alkene products 2-methyl-1-butene and 2-methyl-2-butene. After carrying out steam distillation to isolate the organic alkenes from aqueous components within the reaction mixture, the purity and characterization of the products were then assessed through various analytical methods including Gas Chromatography (GC), Infrared Radiation (IR) Spectroscopy, and Nuclear Magnetic Resonance (NMR) Imaging. Through the characterization of the final products, it was found that little impurities remained in the final reaction solution and according to the GC, no alcohol remained in the vial after the reaction was complete. The actual yield
The first step in preparing the ester involved placing 10mL of an alcohol, 1-butanol, and 10mL of an carboxylic acid, ethanoic acid, in a 50mL pear-shaped flask in the staff fume hood. An alcohol and carboxylic acid was added together as they undergo an oxidation reaction together that produces an ester as a result, in this case, 1-butyl-ethanoate. After this, the teacher added 1mL of concentrated sulphuric acid (H2SO4) into the pear-shaped flask to be used as a catalyst to increase the rate of reaction between the two reactions, 1-butanol and ethanoic acid. The sulphuric acid acts as a catalyst by lowering the activation energy of the reactants, and therefore, providing an alternative path with a lower energy for the reactants to react, ultimately
The purpose of this lab was to synthesize the ester isopentyl acetate via an acid catalyzed esterification (Fischer Esterification) of acetic acid with isopentyl alcohol. Emil Fischer and Arthur Speier were the pioneers of this reaction referred to as Fischer Esterification. The reaction is characterized by the combining of an alcohol and an acid (with an acid catalyst) to yield and ester plus water. In order to accomplish the reaction, the reactants were
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.
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.
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.
This was concluded by combining information on melting points and TLC; melting range narrowed when filtered product was mixed with the standard product. Also, the Rf value of the pure product is closely related to the Rf value of the standard. TLC of filtrate showed no movement of the substance in the mixture under 9:1 ratio declaring the substance to be extremely polar. Of the three potential unknown reactants, 4-methoxyphenol would be the most polar and therefore would travel least up the TLC plate. (Q14:Yield) 81.2% product yield was collected. “Matter cannot be created nor destroyed”, therefore some product could have filtered through. TLC of filtrate confirmed remnants of product present. Filtering the filtrate could have increased the yield. (Q15:Recovery) The percent recovery of the product makes sense because it is the mass of the crystallized product divided by the crude product: 94.9%. The percentage reflects the mass of pure product (without the presence of impurities). (Q16:MP) Melting point coincides with the unknown nucleophile being 4-methoxyphenol because when the standard product was combined with our pure product, the melting range narrowed. When compared to the melting ranges obtained when mixed with the other two possible products the melting ranges significantly decreased and widened. This is often an indication of impurities being present, but because this was a
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