Question

Write chemical equation of five chemical properties of amines.

Hint:

Amines are basic and nucleophilic: remember acylation, alkylation, carbylamine (only 1$^\circ$), and diazotization (aromatic 1$^\circ$).

Answer 1

Part–I: Five chemical properties of amines (with equations)
1) Basic character (salt formation):
\[ \mathrm{RNH_2 + HCl \rightarrow RNH_3^+Cl^-} \]
2) Acylation (Schotten–Baumann):
\[ \mathrm{RNH_2 + R'COCl \xrightarrow{NaOH} R'CONHR + HCl} \]
3) Alkylation (Hofmann exhaustive alkylation):
\[ \mathrm{RNH_2 + R'X \xrightarrow{EtOH} R_2NH \xrightarrow{R'X} R_3N \xrightarrow{CH_3I,\,Ag_2O,\,\Delta} \; \text{quaternary ammonium hydroxide}} \]
4) Carbylamine reaction (test for 1$^\circ$ amines):
\[ \mathrm{RNH_2 + CHCl_3 + 3KOH \xrightarrow{\Delta} RNC + 3KCl + 3H_2O} \]
5) Diazotization / coupling (aromatic 1$^\circ$ amines):
\[ \mathrm{C_6H_5NH_2 + NaNO_2 + 2HCl \xrightarrow{0{-}5^\circ C} C_6H_5N_2^+Cl^- + 2H_2O + NaCl} \]
\[ \mathrm{C_6H_5N_2^+Cl^- + C_6H_5OH \xrightarrow{NaOH} \; \text{azo dye}} \]