amide group

An amide is a nitrogen-containing compound related to ammonia and amines. Covalent amides are formed by replacing the hydroxyl group of an acid with an amino group. Carboxamides, derived from carboxylic acids, are the most common type. Sulfonamides are related to sulfonic acids. Ionic amides are strongly alkaline and formed with reactive metals.

Simple covalent amides are typically solids with high boiling points and are soluble in water if they have fewer than five carbon atoms. While simple amides aren't abundant in nature, polyamides, which are linked amides forming polymers, are abundant as proteins. Amides undergo hydrolysis, a reaction with water, to form acids and amines, though this reaction is usually slow without catalysts.

Commercially important amides include acetamide and dimethylformamide, used as solvents, and sulfa drugs. Urea, a key amide, is a metabolic product and used in fertilizers and resins. Amide bonds are crucial for linking amino acids in proteins.1