Which of the following is the best prediction of the chemical shifts for the signals in the ¹H NMR spectrum for the following compound?

Question

Quizplus · Accepted Answer

I. The proton attached to the nitrogen (N-H) is typically found around 1-2 ppm in the NMR spectrum, so a chemical shift of 1.1 ppm for signal I is reasonable.
II. The two protons adjacent to the carbonyl group (C=O) are typically found around 2-3 ppm in the NMR spectrum, so a chemical shift of 3.2 ppm for signal II is reasonable.
III. The protons in the aromatic ring are typically found around 6-8 ppm in the NMR spectrum, but the presence of the nitrogen in the ring may cause some deshielding, resulting in a slightly lower chemical shift. A chemical shift of 1.4 ppm for signal III is reasonable.
IV. The protons attached to the methyl group (CH3) are typically found around 0-1 ppm in the NMR spectrum, so a chemical shift of 0.9 ppm for signal IV is reasonable.

Which of the Following Is the Best Prediction of the Chemical