There are no practical natural sources of simple covalent amides, although polyamides (amides linked together to form large molecules called polymers) occur in great abundance as the protein of living systems. Simple amides ordinarily are prepared by reaction of acids or acid halides with ammonia or amines.
Are amides found in nature?
The prevalence of amides can be seen in Nature in proteins, peptides and many amide-bond containing biomolecules as well as in many synthetic compounds with diverse applications e.g. as pharmaceutically active compounds or synthetic polymers.
How are amides formed?
The addition of ammonia (NH3) to a carboxylic acid forms an amide, but the reaction is very slow in the laboratory at room temperature. Water molecules are split out, and a bond is formed between the nitrogen atom and the carbonyl carbon atom. In living cells, amide formation is catalyzed by enzymes.
