Acetamide

Acetamide is the amide $\mathrm{C}{\mathrm{H}}_3\mathrm{CON}{\mathrm{H}}_2$. Donation of the nitrogen lone pair into the carbonyl system gives the carbon-nitrogen bond partial double-bond character.

This favors a relatively planar local geometry and reduces nitrogen basicity compared with a simple amine. Acetamide provides a small-molecule model for the electronic features of the peptide bond.