Fischer Esterification
By Bohlin
Abstract:
In this experiment, an unknown alcohol underwent a Fischer Esterification reaction by reacting it with acetic acid as well as sulfuric acid catalyst. The unknown product material was purified through distillation and characterized by analyzing an IR spectrum and determining the density of the product. In addition, the boiling point test was performed to test for an ester. Lastly, the starting material, an unknown alcohol, was determined after finding out the product and examining the IR spectrum for the reactant.
Procedure:
An acetate was synthesized by reacting an alcohol with acetic acid. Since the acetic acid, a carboxylic acid, is less reactive than the acetate, an ester, the sulfuric
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The very strong peak at 1033 cm is due to a o-ch-c stretch and is diagnostic of a o-ch2-c antisymmetric stretch for primary acetates with the literature value of 1060-1030 cm.
Also, the similarity between the database reference of Isobutyl Acetate, reference IR data graph included, and the experimental IR would also suggest that the products are the same and suggest that the unknown reagent was Isobutyl Alcohol.
The density of the product was not able to be recorded due to spillage.
The smell had no distinguishable characteristics to be used for identification.
Based on the boiling point of the ester,119.0 C, the data suggests Isobutyl Acetate was the product and would suggest Isobutyl Alcohol as the unknown alcohol reagent.
Based on the supporting data above it is suggested that the unknown alcohol was Isobutyl Alcohol.
References:
IR Spectra Database -
In an oxidation reaction, the number of C-H bonds decreases or the number of C-O bonds increases, while in a reduction reaction, the number of C-H bonds increases or the number of C-O bonds decreases. In the oxidation step of this reaction, 4-tert-butylcyclohexanone is formed from when a C-H bond is lost while a C-O bond is gained to create a carbonyl. In the reduction step, 4-tert-butylcyclohexanol is formed when the carbonyl is converted into an alcohol when a nucleophilic hydride attacks the carbonyl. Whether the OH is in the
Based on these characteristic properties, groups determined that Fraction 1 was pure isopropanol. Fraction 2 had an inconstant boiling point, a medium odor like alcohol, was flammable, had a density of about 0.93g/100cm3, and dissolved sugar slightly. Since this had an inconstant boiling point and was between plateaus, groups can determine that this was a mixture of isopropanol and water. Fraction 3 had a boiling point of about 100°C, no odor, was not flammable, a density of about
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
Salicylic acid was esterfied using acetic acid and sulfuric acid acting as a catalyst to produce acetylsalicylic acid and acetic acid. The phenol group that will attack the carbonyl carbon of the acetic anhydride is the –OH group that is directly attached to the benzene since it is more basic than the –OH group attached to the carbonyl group. This method of forming acetylsalicylic acid is an esterification reaction. Since this esterification reaction is not spontaneous, sulfuric acid was used as a catalyst to initiate the reaction. Sulfuric acid serves as the acid catalyst since its conjugate base is a strong deprotonating group that is necessary in order for this reaction to be reversible. The need for the strong conjugate base is the reason why other strong acids such as HCl is not used since its conjugate base Cl- is very weak compared to HSO3-. After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in
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.
Condensation reaction is a chemical reaction that joins two reactants to form a larger molecule with the loss of a small molecule, usually water. 1 This reaction is used as a basis for many important process in the plastic/food industry. The most common being the formation of ester, also known as esterification. When a carboxylic acid is reacted with alcohol in the presence of a dehydrating agent, ester and water molecule are formed as products:
This means that unknown compound A was cyclohexanol and it produced the product cyclohexanone. This was able to be found through the IR of the alcohol, the product, and fingerprint spectra all matching the samples
There are four main regions of IR absorptions: region 4000 – 3000 cm-1 corresponds to N-H, C-H and O-H stretching, region 2250- 2100 cm-1 is triple-bond stretching , region 2000- 1500 cm-1 is double bonds and the region below 1500 cm-1 is the fingerprint region where a variety of single bonds are absorbed.3 The chromic acid test is a test for oxidizability and gives a positive result for primary and secondary alcohols as well as aldehydes2. A positive result in the chromic acid test is indicated by a color change and the formation of a precipitate. Tertiary alcohols give negative results for the chromic acid test since there must be a hydrogen present on the alcoholic carbon for oxidation to occur. The 2,4 DNP test, tests for a carbonyl and is therefore a dependable test for aldehydes and ketones. Finally, 13C NMR spectroscopy is a test to determine the structure of a compound. 13C NMR detects the 13C isotope of carbon. Each carbon has a different chemical shift. A carbon’s chemical shift is affected by the electronegativity of nearby atoms. Carbons that are bonded to highly electronegative atoms resonant downfield because the electronegative atom pulls electrons away from the nearby carbons and cause those carbons to resonant downfield1 (John McMurry, 2008). A general trend is that sp3-hybridized carbons absorb from 0 to 90 ppm, sp2-hybridized carbons resonant between 110
form an ester, unreacted 1-phenylethanol, and vinyl alcohol. The unreacted 1phenylethanol was separated from the ester by column chromatography and confirmed by
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.
I can narrow down my unknown substance to either Ethanol or 2-proponal. Ethanol’s density is only 0.001g/mL higher than my own measurements, but its boiling point is 8.4̊C lower than GNR’s. Whereas 2-proponal’s density is off by 0.003g/mL and its boiling point is only off by 4.5̊C. If I were to make an educated guess I would lean more towards Ethanol. Both the precision and accuracy of my data was far greater in density than in boiling point and Ethanol’s density is closer to GNR’s than any other substance.
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
For this experiment, Alcohol D and Acid 2 reacted in the presence of concentrated sulfuric acid, resulting in a colorless solution with brown layer on top. After washes with sodium bicarbonate and brine, the pale-yellow liquid product was dried and then distilled. Distillation resulted in two colorless fractions, the second of which had a boiling point of 69-70 ˚C. This boiling point is unrealistic for any compound obtained in this experiment, so it was not used in identifying the product. After distillation, both fractions were spectroscopically analyzed. The IR and NMR spectra obtained for both fraction were identical, meaning both fractions contained exactly the same substance. Both fractions also smelled the same, like piña colada, therefore confirming this conclusion. This outcome also meant that the amount of product synthesized was 5.7393 g.
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
If I was to do an experiment like this again I could use a different variable instead of alcohols. Instead I could investigate a chain of alkanes or alkenes, “in order to test alkenes I would have to look into the association double carbon bonds have with one