Chemical Sciences

Organic Chemistry

Nitrogen Functional Groups

Introduction to Nitrogen Functional Groups

Nitrogen can be attached to carbon in many ways. The organic compounds which contain nitrogen are essential to life. The most important organic nitrogen compounds are the amines and their derivatives the amides.
Amines
Substitution of an ammonia for hydrogen or carbon produces an amine group on an organic compound. Amines are classified as primary, secondary, or tertiary depending on the number of carbons which form bonds to the nitrogen. Following the normal organic practice of designating a carbon chain by the symbol R, a primary amine would be an amine with the structure RNH2; a secondary amine would have the structure R2NH; and a tertiary amine would have the structure R3N. The carbon chains on a secondary or tertiary amine need not be identical.

Amines, like ammonia, can be protonated giving rise to alkylammonium ions. An example is the ethylammonium ion, CH3CH2NH3+, which is the conjugate acid of ethylamine. Amines are basic and form the largest and most significant class of organic bases.

Amides
A reversible reaction between an amine and a carboxylic acid causes loss of water and the formation of an amide; the reaction is RNH2 + R'COOH --> R'CONHR + H2O. The amide bond is reasonably stable. When it forms between amino acids, in which both an amine group and a carboxylic acid group are present in the same molecule, the polymeric chain produced is a polypeptide. If the polypeptide chain is long enough, it is called a protein.
Copyright 1996 James A. Plambeck (Jim.Plambeck@ualberta.ca). Updated April 26, 1996 jp.
24.8. HETEROCYCLIC COMPOUNDS Incorporation of an oxygen, a nitrogen, a sulfur, or an atom of a related elementinto an organic ring structure in place of a carbon atom gives rise to a heterocyclic compound. Since the heterocyclic atom must form more thanone bond in order to be incorporated into a ring structure, halogens do not form heterocyclic compounds although they may be substituents on a heterocyclic ring structure. Heterocyclic compounds, like polycyclic ring compounds, are usually known by non-systematic names. STUDY PROBLEMS 24.1. Name the following organic compounds. a. C2H5Br; b. CH3CH2(-NH2)CH2CH3; c. (CH3)3 C CH3; d. CH2 = CH2 ; d. HCCH ; e. C3H8; f. C2H5OH (trivial name: grain alcohol); g. CH3CH(-I)CH2CH2CH3 24.2. Write structures for the following organic compounds. a. 2-butyl chloride b. 1-chloro, 2-iodopentane c. 2-pentene d. 3-methylhexene e. 2,3-dimethylhexene f. octyl alcohol (1-octyl alcohol, 1-octanol) g. ethylamine h. propyl bromide (1-propyl bromide) 24.3. Name the following organic compounds. a. Cl CH2CH2COOH b. CH2 = CHCH2CH2COOH (follows -ane -ene system) c. C7HCOOH d. CH3CHO e. CH3CO C2H5 24.4. Write structures for the following organic compounds. a. 1-aminovaleric acid; b. 2-hexenoic acid; c. caproyl aldehyde; d. pentyl hexyl ketone; e. 2-fluoro-6-aminodecanoic acid.