linguistic:voice_change, information:classification, structural:reformatting
Conversion to imines

Imine formation is an important reaction. Primary amines react with ketones and aldehydes to form imines. In the case of formaldehyde (R' = H), these products typically exist as cyclic trimers: RNH 2 + R 2 ′ C = O ⟶ R 2 ′ C = NR + H 2 O {\displaystyle {\ce {RNH2 + R'_2C=O -> R'_2C=NR + H2O}}} Reduction of these imines gives secondary amines: R 2 ′ C = NR + H 2 ⟶ R 2 ′ CH − NHR {\displaystyle {\ce {R'_2C=NR + H2 -> R'_2CH-NHR}}}

Similarly, secondary amines react with ketones and aldehydes to form enamines: R 2 NH + R ′ (R ″ CH 2) C = O ⟶ R ″ CH = C (NR 2) R ′ + H 2 O {\displaystyle {\ce {R2NH + R'(R''CH2)C=O -> R''CH=C(NR2)R' + H2O}}}

Mercuric ions reversibly oxidize tertiary amines with an α hydrogen to iminium ions: Hg 2 + + R 2 NCH 2 R ′ ↽ − − ⇀ Hg + + + H + {\displaystyle {\ce {Hg^2+ + R2NCH2R' <=> Hg + + + H+}}}