Fischer Esterification

Ethyl ethanoate: Ethyl ethanoate is an ester. Esters are group of organic compounds which have a functional group of –COO-. Esters are liquids that become vapours quickly so they are present in perfumes.

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.

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

The purpose of this experiment was to synthesize t-pentyl chloride from the reaction of t-pentyl alcohol and concentrated HCl. This reaction occurred through an SN1 reaction, a unimolecular nucleophilic substitution reaction. This was a First Order Rate Reaction where the rate of t-pentyl chloride was dependent only on the concentration of t-pentyl alcohol. After the reaction was completed, the products were achieved via 3 liquid-liquid extractions and then after by simple distillation. In the liquid- liquid extractions a solute was transferred from one solvent to another. Then in the simple distillation the miscible liquids or the solution, was separated by differences in boiling points. After this the product was determined through infrared spectroscopy.

The crude product was washed by taking the reaction product in the separatory funnel and adding 23 mL of deionized H2O. The mixture was shaken and allowed to settle until layers were observable. The top layer was the desired product and approximately 25 mL of aqueous layer was extracted from the separatory funnel. Next, 25 mL of 5% NaHCO3 was added to the separatory funnel in order to neutralize the acid. This mixture was swirled, plugged with the stopper and inverted. Built-up gas was released by turning the stopcock to its opened and closed positions, releasing CO2 by-product. This was done four times in one minute intervals. The solution was allowed to settle until layers were observable. The bottom layer that contained salt, base and water was extracted from the separatory funnel. The crude product was washed again as mentioned previously.

The experiment began by mixing the initial 1.775g isopentyl alcohol with 2.3 mL acetic acid and about 5 drops sulfuric acid. This reaction mixture was then heated under reflux for an hour after boiling of the reaction mixture began.

Wash (swirl and shake) the organic layer with one 10-mL portion of water and again drain the lower aqueous layer. Transfer the organic layer to a small, dry Erlenmeyer flask by pouring it from the top of the separatory funnel. Dry the crude t-pentyl chloride over 1.01 g of anhydrous calcium chloride until it is clear (see Technique 12, Section 12.9). Swirl the alkyl halide with the drying agent to aid the drying.

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

In this specific esterification process Butyl Pentanoate will be synthesized by reacting Butan-1-ol with Pentanoic Acid, shown in the equation below

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.

Infrared spectroscopy (IR) is a very useful tool that can read a molecule’s functional groups from a small sample. By monitoring the disappearance and appearance of certain groups, it is possible to confirm wether compounds have formed. In this experiment, for example, the reactants are alcohols, whose IRs will show a large and broad absorption around 3500 cm-1. These hydroxide groups are eventually replaced during the reactions, and the final products will not contain any hydroxides. Therefore, the IR of the products will not show the large and broad hydroxide absorption. Monitoring the disappearance of the hydroxide stretch will allow the reaction progression to be monitored also. The complete disappearance of this stretch will confirm that a new product has been formed. However, IR

The aim of this practical is to produce the ester, 3-methylbutyl ethanoate (isoamyl acetate) through esterification of its alcohol and carboxylic acid components. This will require expert understanding and operation of reflux, isolation and distillation processes.

In this experiment, we made an artificial ester called pentyl ethanoate, also known as pentyl acetate, and analyzed its physical and chemical properties. The method used in the experiment is an esterification reaction. We synthesized pentyl ethanoate by mixing equal amounts of 1-pentanol and ethanoic acid in the presence of a few drops of sulfuric acid, which is a strong acid catalyst. The mixture of the reactants was heated for ten minutes in a hot-water bath at a temperature of sixty degrees Celsius and was given time to cool in a different beaker for five minutes. The product formed was a colorless, insoluble liquid that smelled like banana candy. Two minutes later, a reverse reaction had occurred and the aroma of banana changed to a marker smell. The pentyl ethanoate was on the surface of the water mixture while the sulfuric acid, ethanoic acid, and 1-pentanol were dissolved into the bottom of the water mixture. These findings helped us understand the importance of synthesizing esters, the physical and chemical properties of artificial esters, and how the esterification reaction between an alcohol and a carboxylic acid such as between 1-pentanol and ethanoic acid can form a pleasant banana aroma ester, such as pentyl ethanoate.

In this experiment, two organic esters, aspirin or commonly known as acetylsalicylic acid and methyl salicylate (oil of wintergreen) were synthesized through an esterification process and then the purity of some of the molecules was determined through analytical techniques.

By using acid-base extraction techniques, a three-component mixture was separated into its individual components which included an acidic, basic, and neutral component as previously mentioned. A separatory funnel was the mechanism used to carry out this procedure. Its easy handling allowed for thorough mixing of the solution. It was equipped with a stopper which was opened to release pressure from inside the funnel caused by the heat from one’s hands and also the reactions taking place within it (1). Without inverting the funnel and relieving pressure the funnel would’ve exploded. The stopcock was useful for precisely drawing off each layer. However, if the separatory funnel had been shaken too violently an emulsion would’ve formed. An emulsion is when the layers do not clearly separate. Instead, one cloudy layer will form. During this procedure an emulsion was avoided by using proper gently swirling technique.