Synthesis of Salicylic Acid from Wintergreen Oil

The goal of this experiment was to synthesize aspirin. In this experiment aspirin, also known as acetylsalicylic acid, was synthesized from salicylic acid and acetic anhydride. In the reaction the hydroxyl group on the benzene ring in salicylic acid reacted with acetic anhydride to form an ester functional 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. After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in the solution as well as some sulfuric acid, aspirin, and acetic acid. Crystallization, which uses the principle of

In this experiment, an unknown Grignard reagent was prepared from an aryl halide. The unknown reagent was then reacted with carbon dioxide to form a carboxylic acid. The solid acid was then isolated and recrystallized before the melting point was taken. The precipitate was then dissolved in water and titrated to determine the molecular weight. The melting point and molecular weight were then used to determine the unknown acid obtained from the experiment.

The aspirin crystals were washed by pouring 10 mL of water over them through the funnel.

Based on the 1H NMR spectrum that was collected, a few things can be determined. Based on deshielding and electronegativity, the peak that occurs around 4.7ppm is associated with the O-ethylsaccharin product and the peak at 3.8 ppm is associated with the N-ethylsaccharin product. Based on the height ration, the N-ethylsaccharin product is the more prevalent result.

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

Figure 2: Gas Chromatography analysis from the first sample. From top to bottom the peaks are ordered as followed: 3-methylcyclohexanol (A), 1-methylcyclohexanol (B), and 2-methylcyclohexanol

Objective: The objective of this experiment is to use acid-base extraction techniques to separate a mixture of organic compounds based on acidity and/or basicity. After the three compounds are separated we will recover them into their salt forms and then purify them by recrystallization and identify them by their melting points.

Results: No substantial qualitative data was collected, except that the original reaction mixture turned a purple color. Upon the addition of anise oil and heat, the reaction mixture turned a brown color. And with the addition of NaHSO3 the mixture turned a white color. The mass of the final product sample was measured to be 0.08g (see Calculation 1). The melting point range for this sample was 172.8-185.4ºC in Trial 1 and 171.6-185.2ºC in Trial 2 (see Table 1). The IR spectrum of anise oil can be found attached. Peaks appear to exist at 3022.86, 3002.41, 2957.58, 2933.88, 2912.63, 2834.94, and 2723.19 (cm-1). Another set of peaks appear to exist at 1608.06, 1510.55, 1464.73, 1441.16, 1306.3, 1283.06, 1247.18, 1174.78, 1036.26, 964.58, 839.29, and 787.03 (cm-1). No other significant quantitative results were collected.

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

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.

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 experiment is to separate a mixture of salicylic acid and naphthalene using extraction, recrystallization and sublimation techniques. Extraction is the separation of compounds from a mixture based on their relative solubilities in different solvents. Sublimation is the process of separation by which a substance transitions from the solid phase into the gas phase, skipping the liquid phase. Recrystallization involves dissolving a substance in an appropriate solvent then crystallizing it as it cools (impurities remain in solution). The melting points of the substances were determined in order to assess their purity and the percent recovery of pure naphthalene and salicylic acid were calculated. According to the results, the melting point of pure naphthalene was between 86°C -89°C range, whereas for pure salicylic acid was 167°C -170°C. Both determined melting points were higher compared to the literature value of 80.26°C and 158.6°C for pure naphthalene and salicylic acid respectively. Lastly, the percent recovery for pure naphthalene and salicylic acid were 17.7% and 71.2% accordingly.

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.

This report presents the synthesis of Aspirin (acetylsalicylic acid), as the product of the reaction of salicylic acid with ethanoic anhydride under acidic conditions. Aspirin was purified through recrystallisation by vacuum filtration, followed by desiccation of the Aspirin crystal over silica gel. The percentage yield was calculated as 44.89% and a sample of Aspirin was analysed using infra-red spectroscopy and compared to the spectrum of pure Aspirin, this served as an introduction to the identification of functional groups in organic compounds. The melting point was calculated using an IA9000M apparatus and recorded to be 35.2°C, which was slightly below the melting point of pure Aspirin; known to be between 138-140°C. Both IR spectroscopy and melting point measurement were used verify the purity of synthetic Aspirin made, which proved to be fairly pure under these laboratory conditions.