Amines and Amides

Amines Amines are organic molecules that are similar to ammonia (NH3), except that are least one of the hydrogen atoms is replaced by a carbon atom. For example: Ammonia ethanamine N-methylmethanamine

Classification of Amines Since one, two or three hydrogens can be replaced in ammonia, amines can be classified as primary, secondary or tertiary.

Nomenclature of Amines Amines are named as alkanamines. These names are obtained by replacing 'e' from the name of the parent alkane with suffix amine. ethanamine

Nomenclature of Amines If more than one hydrogen are replaced, then the substituents are named as alkyl groups. Since they are attached to the nitrogen, N is written instead of a number. One N is written for each substituents. The substituents are listed alphabetically. Example; N,N-dimethylmethanamine N-methylethanamine N-ethyl-N-methylpropanamine

Reactions of Amines Amines are weak bases, just like ammonia. The Lewis structures for ammonia and amines indicate that the nitrogen atom has a lone electron pair available to be used as a proton acceptor. Additionally, they can accept a proton (H+) from water, increasing the (OH-) concentration. Because they react as bases, they will react with any proton donating substance. In the reaction with water, an ammonium ion and a hydroxide ion will form. Ex. Ammonia + water → ammonium + hydroxide

Amides Amides are neutral compounds. Amides may be considered to be amine derivatives of carboxylic acids. The amide bond is very important in biochemistry since it is the essential link for amino acids in protein molecules. In protein molecules, the amide functional group is called a peptide bond. An example of a common amide is ethanamide:

Reactions of Amides The most important reaction of an amide is its hydrolysis to produce a carboxylic acid and an amine. The reaction can be catalyzed by either an acid or a base and with the addition of heat. In humans the reaction is enzyme catalyzed. enzyme + H2O → amide + water → carboxylic acid + amine

Hydrolysis of Amides

Hydrolysis of Amides The hydrolysis of butanamide: butanamide butanoic acid ammonia