AMINES L.O.:  What are amines?  How are they named?  How do they react?

They can be thought of as derivatives of ammonia in which one or more of the hydrogen atoms have been replaced by an alkyl or aryl group.

primary (1°) amines secondary (2°) amines tertiary (3°) amines R N : H H R H R R

NOMENCLATURE Using the suffix amine C 2 H 5 NH 2 ethylamine (CH 3 ) 2 NHdimethylamine (CH 3 ) 3 N trimethylamine C 6 H 5 NH 2 phenylamine (aniline)

Different substituents are written in alphabetical order methylpropylamine

BOILING POINT Amines have higher boiling points than corresponding alkanes because of their intermolecular hydrogen bonding

Q. Why are the boiling points of amines lower that the comparable alcohols. N is less electronegative than O. Hydrogen bonds are weaker.

SOLUBILITY Primary amines with chain lengths up to C 4 are very soluble in water and alcohols. C 6 H 5 NH 2 is not very soluble.

REACTIVITY OF AMINES The LONE PAIR on the nitrogen atom in 1°, 2° and 3° amines makes them... BRØNSTED-LOWRY BASES - they can be proton acceptors RNH 2 + H + ——> RNH 3 + NUCLEOPHILES - provide a lone pair to attack an electron deficient centre