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The nucleophilic nature of amines

The nitrogen atom of primary, secondary and tertiary amines bears a free doublet. Since the electronegativity of nitrogen is not as high as that of eg oxygen ($ En_N = 3 \; \le \; En_O = 3.5$), this doublet is less well retained, which causes the amines to be stronger →       nucleophiles than alcohols:

$R_1,R_2,R_3$ = hydrocarbon chain or hydrogen atom

Amines are nucleophiles

Exemples

- Reactions with acid chlorides →  see details: $CH_3C=OCl$$+$$CH_3CH_2NH_2$ $\rightarrow$ $ CH_3C=ONHCH_2CH_3 +HCl$ Ethanoyl chloride and ethylamine give N-ethylethanamide

Amines react with acid chlorides to form nitrogen-substituted amides

- Reactions with halogenoalkanes →  see details: $CH_3I$$+$$2\;CH_3CH_2NH_2$ $\rightarrow$ $ CH_3CH_2NHCH_3 +CH_3CH_2NH_3^+I^-$ Iodomethane and ethylamine give ethylmethylamine + ethylammonium iodide

Amines react with chloro-, bromo- or iodoalkanes to form nitrogen-substituted amines