The first peak ppm comes from the carbons the image

Leone Akhmeteli CHEM 432L
Extra Point Assignment
Experiment: Preparation of Methyl Benzoate Compound: Methyl Benzoate (C6H5COOCH3) 1. IUPAC Name: Methyl Benzoate
2. Chemical Structure:

We do not pay attention to the fingerprint region (below 1500 cm-1) On the image above C=C bond peak can be seen around 1400-1600 cm-1, which occurs from the C=C bonds in the aromatic ring. Next to the left is the peak occurring from C=O bond, indicating a carbonyl group present in the compound. The presence of aromatic ring is also proved with series of small peaks between 1900-2200 cm-1.

4.Signals of C13 and H1 NMR Spectrum Characteristic:

There are five distinct peaks on the C13 NMR Spectra of Methyl Benzoate. Each peak represents carbon atom in different region. Peak around 160-186 ppm is due to C=O bond in esters, it is also the most dramatic peak (highest) since oxygen atom is the most
electronegative element in this compound. There is also a peak near 132 ppm, which indicates the presence of highly substituted carbon. Aromatic peaks occur on 100-150 ppm, matching our structure for this compound. The peaks for esters are approximately in the range of 150-180 ppm, also matching the structure of methyl benzoate.

3. Main Peaks in IR Spectrum:

There would be four peaks on the graph (the fourth one not seen well on the image above) coming from different regions. Since the compound is aromatic, as always, there would be a shift around 7-8 ppm. The compound also contains carboxylic acid group; therefore, proton shift should be expected at about 11-13 ppm (1H). There is symmetry between ortho and meta hydrogens. The ortho hydrogens peak at 8.12 ppm and have triplets, which indicates presence of two hydrogen atoms on the adjacent carbon. Meta hydrogens also have triplets; however, they give different hydrogen shift, since they are closer to the carboxylic acid group. The other two peaks come from para hydrogen (farthest from the COOH group) and the hydrogen of carboxylic acid group itself. The carboxylic acid proton peak is a singlet since there are no adjacent hydrogens. It is also the highest peak since it is close to the most electronegative atom in the molecule.

Experiment: Chlorination of Caffeine

Main Product: Chlorinated Caffeine

3. IR spectra of Chlorinated caffeine:

C=O C=C

I marked all of the 1H regions that give peaks with blue. There would be a total of three (3H) peaks at about 3-4 ppm. All the three peaks would be singlets since there are no adjacent hydrogens on neighbor carbons. The peak at 3.2 ppm is due to CH3-N in the molecule. NH shift may occur anywhere from ~0-5.5 ppm. The C=C hydrogens give different peaks due to the nitrogen atom being closer to one of the carbons. Therefore, there are only three peaks in total.

There would be two peaks at 165-175 ppm, due to amide group carbon. And around 30-60 ppm there would be C-N shift. The peak for C-Cl would be around 25-50 ppm (no chlorine in the image).

By product: Succinaminide
1. IUPAC name: Pyrrolidine-2,5-dione
2. Structure:

There is a very sharp peak of C=O bond around 1700 cm-1, indicating the presence of carbonyl group. A stretch around 1800-2100 cm-1 is indication that N-H bond is present. We can also make that assumption if we look at a small peak and stretch at ~3400-3700 cm-1 also for the N-H bond. Obviously, an sp3 hybridization peak is often seen around 2800-3000 cm-1, indicating the sp3 hybridization of carbon; howerver, no sp2 is seen around 3100 cm-1 which also proves our structure of succinimide.

4.Signals of C13 and H1 NMR Spectrum Characteristic:

Just like 1H NMR Spectra, 13C only gives two peaks. Both peaks are singlets (again, no adjacent hydrogens present). The first peak at 30.30 ppm comes from the carbons #2 (2 in the image). It can be concluded from the fact that amide carbon peaks at ~180 ppm. Also, the peak of the first carbon is much greater due to the oxygen atom being closer.