Q47E - Organic Chemistry (Mcmurry)

Question

Nitriles, R - C = N , undergo a hydrolysis reaction when heated with

aqueous acid. What is the structure of the compound produced by hydrolysis of propanenitrile, CH₃CH₂C=N , if it has IR absorptions from 2500-3100cm^-1 and at 1710cm^-1 , and has M⁺ = 74?

Step-by-Step Solution

Answer

IR spectroscopy

The N-H functional group of amine can be easily detected using the IR spectroscopy. It shows a characteristic absorption in the range 3300 to 3500cm^-1 . An N-H absorption band is less intense in comparison to the O-H absorption band.

Structure of the compound from the given data

The m/z value of the product is 74. The IR spectrum shows that the compound has IR absorptions at the values 2500-3100 cm^-1 and at 1710 cm^-1 .

When the nitrile undergoes hydrolysis forms carboxylic acid. The given propane nitrile, CH₃ CH₂ C = N undergoes hydrolysis to give propionic acid.

IR absorptions at the values from 2500-3100 cm^-1  indicates the hydroxyl group at the carboxylic acid. The value at 1710 cm^-1 indicates the carbonyl group of the carboxylic acid functional group.

The molecular weight of the compound matches with the expected compound. The structure of the compound can be given as: