|Structure of Amines
||Structure of amines, and aryl amines,
|| Classification- 1°, 2°, 3°
|Preparation of Amines
||Reduction of nitrobenzene, reduction of nitrile and amide – general reactions and examples (R=CH3, C2H5), ammonolysis of alkyl halides -general reactions only – up to quaternary ammonium salt, Gabriel phthalimide synthesis -general reaction and example with R=CH3, Hoffmann bromamide degradation reaction -general reaction and examples (R=CH3, C6H5)
||1. Compare boiling point and solubility of 1°, 2°, 3° amines.
2. Compare base strength of NH3, CH3NH2 and C6H5NH2 in aqueous medium.
3. Compare the trends in the base strength of methyl substituted amines in gaseous state and in aqueous medium.
||Acylation – acetylation for 1° and 2° amine using CH3COCl, Carbylamine reaction (test for 1° amine), and reaction with nitrous acid – general reaction and examples (R=CH3, C2H5, C6H5) Reaction with Heinsberg’s reagent to identify/ distinguish 1°, 2°, 3° amines. Electrophilic substitution reactions for aniline: bromination, nitration (significance of acetylation) and sulphonation. Cyanides and isocyanides.
|Importance of Diazonium Salts in Synthesis of Aromatic Compounds
||General formula ArN X2. Example: C6H5 N2 Cl, C6H5 N2 H SO4 Preparation from aniline-diazotisation, chemical reactions: Sandmeyer’s reaction -replacement of diazo group by Cl, Br, CN, replacement of diazo group by I and H (reduction using H3PO2). Retention of diazo group: coupling reaction- formation of azo dyes, example – C6H5N2Cl with aniline and phenol. Importance in synthetic organic chemistry.