Chapter 24 — Chapter 24 — Organic Nitrogen Compounds

Organic nitrogen compounds form the basis of life (amino acids, nucleotides, proteins) and are important in dyes, medicines, polymers (nylon, Kevlar, polyurethane), fertilisers and explosives. Amines are organic derivatives of ammonia in which alkyl or aryl groups replace one, two or three hydrogen atoms. In primary amines one alkyl or aryl group is attached to –NH₂ (methanamine CH₃NH₂, ethanamine, propan-1-amine, phenylamine/aniline). In secondary amines two groups are attached to NH (N-methylmethanamine, N-methylethanamine, diphenylamine). In tertiary amines three groups are attached to the same N (N,N-dimethylmethanamine, triphenylamine). Tetra-substituted derivatives are quaternary ammonium salts, e.g. tetramethylammonium chloride [(CH₃)₄N]⁺Cl⁻. It is branching at the nitrogen atom, not at the carbon, that decides whether an amine is primary, secondary or tertiary — unlike alcohols and alkyl halides. In IUPAC, amines are alkanamines.