Amines - Topic 18

how can amines be classified

aliphatic and aromatic

what feature do aliphatic amines have

alkyl groups attached to the nitrogen atom

what feature do aromatic amines have

nitrogen atom bonded directly to a benzene ring

where do amines come from

when hydrogens on ammonia are replaced with alkyl or aryl groups

what are primary amines

one hydrogen has been replaced

what are secondary amines

two hydrogens replaced

what are tertiary amines

three hydrogens replaced

what are quaternary ammonium ions

four organic groups attached to positively charged nitrogen

how are amines able to act as weak bases

nitrogen atom has lone pair of electrons

why are aliphatic amines stronger bases than aromatic amines

the electron density of the nitrogen is reduced in aromatic amines by partial delocalisation and aliphatic amines have electron-donating alkyl groups increasing the electron density

why are small amines highly soluble

hydrogen bonds can form

what forms when amines dissolve in water

alkaline solutions

why do amines form alkaline solutions when dissolved in water

amine molecules accept a proton from water

what are the two methods of producing aliphatic amines

nucleophilic substitution of halogenoalkanes, reduction of nitriles

what is the reagent for the reaction of halogenoalkane to produce aliphatic amines

excess ethanolic ammonia

how can secondary aliphatic amines be produced

halogenoalkane and primary amine

how can tertiary amines be produced

halogenoalkane and secondary amine

how do you form quaternary ammonium salts

halogenoalkane and tertiary amine

how are nitriles reduced to form amines

nitrile is reacted with hydrogen gas in the presence of a metal catalyst

how are aromatic amines formed

nitro compound is heated under reflux with tin and concentrated HCl to form an ammonium salt, ammonium salt treated with NaOH (aq)