The purpose of this lab was to synthesize acetanilide and use recrystallization to isolate the acetanilide product from small amounts of impurities, acetic acid. Recrystallization is a very effective way for organic chemists to isolate a solid product from a small amount of impurities but cannot be used for liquids. The crude acetanilide product and the recrystallized acetanilide were compared using melting point determination and the recrystallized product was then classified and checked for impurities by determination of IR and 1H NMR spectra.
Results and Discussion For this lab, a nucleophilic acyl substitution reaction was carried out to synthesize acetanilide from aniline and acetic anhydride. In this reaction, the lone pair of electrons …show more content…
These values are good considering the excess precipitate that stick to the walls of the reaction flask and the crude product lost to melting point determination and recrystallization solvent determination. It is expected that higher yields could be made without the removal of crude product from the two steps. From the 1H NMR spectra we expected to see peaks in the aromatic region around 6.5-8.0 PPM (5 H), a broad N-H peak around 8 PPM (1H) and a methyl group singlet peak around 2.2 PPM (3H). The 1H NMR spectra follows the expected spectra almost exactly as all the major peaks are present. While the aromatic splitting patterns are close together the correct integration value of roughly five is present. There are no additional hydrogen peaks that would suggest an impurity or any major shifts that were not expected. This further suggests that the pure acetanilide product was indeed created. From the IR graph peaks at 3293.91, 3197.65, 3137.42, 3059.68, 1661.46, and 1434.30 cm-1 are observed as predicted in the prelab report. The N-H peak can be seen at 3293.91, and the aromatic C-H bonds can be seen from 3197-3059 cm-1. We also see the expected carbonyl group peak at 1661.46 cm-1. The only unexpected peaks that can be seen are those from 2335.17-1972.32 cm-1. The peaks in this region indicate a triple bond and assume that some may have been formed between carbon …show more content…
Making sure that a proper recrystallization solvent is used is the most time consuming and crucial part of recrystallization. Without the correct solvent the solute will not recrystallize or the dissolve at all. Verification that the pure acetanilide was produced is observed by the determination of the melting points of the crude and recrystallization product as well as determination of the IR and 1H NMR spectra on the recrystallization product. From the melting points it’s observed that that the melting point of the recrystallization product was higher than that of crude product, 115°C and 116°C respectively. Also, from the 1H NMR it is observed that the 8.0 PPM (s, 0.56H), 7.4 PPM (m, 5.14 H), and 2.2 PPM (s, 3.00H) peaks correspond to those that were expected to be seen for acetanilide with no additional hydrogen peaks corresponding to impurities. Similarly, the IR peaks at 3293.91 cm-1, 3197.65 cm-1, 3137.42 cm-1, 3059.68 cm-1, 1661.46 cm-1, 1434.30 cm-1 follow the expected peaks that were predicted and further verify that the pure acetanilide product was formed, and the reaction was
Results and Discussion For this lab, a nucleophilic acyl substitution reaction was carried out to synthesize acetanilide from aniline and acetic anhydride. In this reaction, the lone pair of electrons …show more content…
These values are good considering the excess precipitate that stick to the walls of the reaction flask and the crude product lost to melting point determination and recrystallization solvent determination. It is expected that higher yields could be made without the removal of crude product from the two steps. From the 1H NMR spectra we expected to see peaks in the aromatic region around 6.5-8.0 PPM (5 H), a broad N-H peak around 8 PPM (1H) and a methyl group singlet peak around 2.2 PPM (3H). The 1H NMR spectra follows the expected spectra almost exactly as all the major peaks are present. While the aromatic splitting patterns are close together the correct integration value of roughly five is present. There are no additional hydrogen peaks that would suggest an impurity or any major shifts that were not expected. This further suggests that the pure acetanilide product was indeed created. From the IR graph peaks at 3293.91, 3197.65, 3137.42, 3059.68, 1661.46, and 1434.30 cm-1 are observed as predicted in the prelab report. The N-H peak can be seen at 3293.91, and the aromatic C-H bonds can be seen from 3197-3059 cm-1. We also see the expected carbonyl group peak at 1661.46 cm-1. The only unexpected peaks that can be seen are those from 2335.17-1972.32 cm-1. The peaks in this region indicate a triple bond and assume that some may have been formed between carbon …show more content…
Making sure that a proper recrystallization solvent is used is the most time consuming and crucial part of recrystallization. Without the correct solvent the solute will not recrystallize or the dissolve at all. Verification that the pure acetanilide was produced is observed by the determination of the melting points of the crude and recrystallization product as well as determination of the IR and 1H NMR spectra on the recrystallization product. From the melting points it’s observed that that the melting point of the recrystallization product was higher than that of crude product, 115°C and 116°C respectively. Also, from the 1H NMR it is observed that the 8.0 PPM (s, 0.56H), 7.4 PPM (m, 5.14 H), and 2.2 PPM (s, 3.00H) peaks correspond to those that were expected to be seen for acetanilide with no additional hydrogen peaks corresponding to impurities. Similarly, the IR peaks at 3293.91 cm-1, 3197.65 cm-1, 3137.42 cm-1, 3059.68 cm-1, 1661.46 cm-1, 1434.30 cm-1 follow the expected peaks that were predicted and further verify that the pure acetanilide product was formed, and the reaction was