Step 1: Brief Description The given compound is 4-aminobenzoic acid. The IR and NMR spectrum of this compound also given. Determine the spectrum. Step 2: Determination of IR data The peaks are identified as following: Two bands at 3300 & 3230 cm. This is due to asymmetrical and symmetrical N-H stretching of NH₂ group. A broad stretching between $200-2500 cm** - This broad stretching is due to O-H in carboxylic acid group. Band at 1680-1700 cm¹. C=O Stretching 1600 cm C-C-C (aromatic carbon) Step 3: Determination of PMR spectrum Splitting patterns: It should be noted that spin-spin splitting is observed only between nonequivalent neighboring protons. Equivalent protons do spin-spin couple with one another but splitting is not observed. Chemical shift: A highly shielded proton has a low chemical shift and a highly deshielded proton has a high value of chemical shift. The given peaks are of following: Proton Level Chemical shift (ppm) Relative integration Multiplicity ABC -11.9 7.8 8.3 broad singlet (N-H D -5.9 2H proton) 2H %%%% 1H broad singlet (OH proton) 2H doublet doublet b. For the NMR spectrum shown below, draw the structure of the compound next to the spectrum and label the protons so that they match the letter labels shown on the NMR spectrum. Fill in the Chemical shift, integration and multiplicity in the table. You should consider electron donating and withdrawing effects before assigning the aromatic ring protons. Ε B C and D E Note that the actual measured integration values are given above each set of peaks. Also note that the signal from -3.8-4.5 ppm is due to two overlapping signals; A quartet (C) and a very broad singlet (D). Each of these two signas has an integration of approximately 2.0 (the total integration for this combined signal is approximately 4.0 (actual -3.851)) STRUCTURE: Proton label Chemical shift Relative Integration Expected (& Multiplicity (ppm) observed) C. The NMR spectrum shown A B C D E below represents the product (ethyl 4-aminobenzoate) after it has been shaken with deuterium oxide (D₂O). Write the equation for the reaction which occurs when D₂O reacts with ethyl 4-aminobenzoate. Draw the structure of the compound next to the spectrum and label the protons so that they match the letter labels shown on the NMR spectrum. Fill in the Chemical shift, integration and multiplicity in the table. D. on the results of the "D20 shake". What happened to the signal which had been caused by HD? Explain briefly.

Step 1: Brief Description The given compound is 4-aminobenzoic acid. The IR and NMR spectrum of this compound also given. Determine the spectrum. Step 2: Determination of IR data The peaks are identified as following: Two bands at 3300 & 3230 cm. This is due to asymmetrical and symmetrical N-H stretching of NH₂ group. A broad stretching between $200-2500 cm** - This broad stretching is due to O-H in carboxylic acid group. Band at 1680-1700 cm¹. C=O Stretching 1600 cm C-C-C (aromatic carbon) Step 3: Determination of PMR spectrum Splitting patterns: It should be noted that spin-spin splitting is observed only between nonequivalent neighboring protons. Equivalent protons do spin-spin couple with one another but splitting is not observed. Chemical shift: A highly shielded proton has a low chemical shift and a highly deshielded proton has a high value of chemical shift. The given peaks are of following: Proton Level Chemical shift (ppm) Relative integration Multiplicity ABC -11.9 7.8 8.3 broad singlet (N-H D -5.9 2H proton) 2H %%%% 1H broad singlet (OH proton) 2H doublet doublet b. For the NMR spectrum shown below, draw the structure of the compound next to the spectrum and label the protons so that they match the letter labels shown on the NMR spectrum. Fill in the Chemical shift, integration and multiplicity in the table. You should consider electron donating and withdrawing effects before assigning the aromatic ring protons. Ε B C and D E Note that the actual measured integration values are given above each set of peaks. Also note that the signal from -3.8-4.5 ppm is due to two overlapping signals; A quartet (C) and a very broad singlet (D). Each of these two signas has an integration of approximately 2.0 (the total integration for this combined signal is approximately 4.0 (actual -3.851)) STRUCTURE: Proton label Chemical shift Relative Integration Expected (& Multiplicity (ppm) observed) C. The NMR spectrum shown A B C D E below represents the product (ethyl 4-aminobenzoate) after it has been shaken with deuterium oxide (D₂O). Write the equation for the reaction which occurs when D₂O reacts with ethyl 4-aminobenzoate. Draw the structure of the compound next to the spectrum and label the protons so that they match the letter labels shown on the NMR spectrum. Fill in the Chemical shift, integration and multiplicity in the table. D. on the results of the "D20 shake". What happened to the signal which had been caused by HD? Explain briefly.

Organic Chemistry

9th Edition

ISBN:9781305080485

Author:John E. McMurry

Publisher:John E. McMurry

Chapter12: Structure Determination: Mass Spectrometry And Infrared Spectroscopy

Section12.SE: Something Extra

Problem 49AP: The infrared spectrum of the compound with the mass spectrum shown below has a medium-intensity peak...

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