Question

Identify the compound with molecular formulaC₃H₇NO responsible for the ¹H NMR spectrum shown here.

Short answer

The compound is propanamide (CH₃CH₂CONH₂).

Step-by-step solution

Step-by-Step SolutionStep 1: Possible isomers of C3H7NO

1. CH₃CH₂CONH₂ (Propanamide)
2. CH₃CONHCH₃ (N-methylacetamide)
3. CH₃CH₂NHCOH (N-ethylmethanamide)
4. (CH₃)₂N-COH (N-ethyl-N-methylmethanamide)

Interpreting 1H NMR spectrum of propenamide

• The signals in range 1- 1.5ppm region of¹H NMR spectrum indicate a CH₂ group.
• The range 2-2.5, indicate that in the structure, there exists a CH₃ group.
• At the range of 6-7, there is a broad band that indicates the presence of NH₂ group.

From these values we get to know that in the structure, there are 3 possible proton environments. These possible values focus on one structure—propanamide.

Even though C₃H₇NO has 4 isomers, all other structures except propanamide has one proton single peak in ¹H NMR spectrum. This peak is absent in the spectrum of propanamide. Hence, we get to know that the given ¹H NMR spectra is responsible for propanamide compound.