Chapter 18, Problem 18.101P

Interpretation Introduction

Interpretation:

The product with a detailed mechanism for the given reaction is to be drawn by referring to the ${}^{\text{1}}\text{H}\text{NMR}$ signals and IR absorption frequency.

Concept introduction:

In an ${}^{\text{1}}\text{H}$ NMR, the number of signals is equal to the number of types of protons in the molecule. The chemically equivalent protons absorbed at the same magnetic field and produce one signal, whereas the chemically non-equivalent or distinct protons absorbed at different magnetic fields produce different signals. The separation of NMR peaks into a number of smaller peaks is called the splitting of NMR peaks. The non-equivalent protons can couple each other’s signals whereas equivalent protons do not. The multiplicity of the peak depends on the number of neighboring protons, which can be determined by $\text{(}N\text{+1)}$ rule, where $N$ is the number of neighboring protons. If the signal for a particular proton appears as a singlet, and this indicates that the proton has no neighboring protons.

The $\text{OH}$ or $\text{NH}$ proton couples with alkyl proton but do not show spin-spin splitting in ${}^{\text{1}}\text{H NMR}$ spectrum and appear as board singlet.

IR spectroscopy enables to identify different functional groups in the molecule.

One of the greatest advantages of IR spectroscopy is that the frequency of a particular type of vibration is typically found within a characteristic range of frequencies, regardless of the functional group with which the vibration is associated. The fact that absorptions by certain vibrations appear with characteristic frequency ranges enables us to use IR spectroscopy to obtain structural information about a molecule.

The secondary amine can be produced by reacting acetonitrile with an alcohol in an acidic condition.