Amines

Describe the properties of amines.

N atom with lone pair

very electronegative nitrogen

NH bond is polar

H bonding so high boiling points

organic bases

nucleophilic

What are alkaloids?

natural product containing one or more nitrogen heteroatoms.

What are quaternary ammonium ions?

A nitrogen atom with 4 attached groups which are all alkyl/aryl forms quaternary ammonium salts.

What are heterocyclic amines?

Nitrogen atom occurs as part of a ring, the compound is heterocyclic

How is the nitrogen hybridised in an amine?

sp3

What shape is the bonding in an amine?

tetrahedral or trigonal pyramidal depending on inclusion of the electron pair

Why is there weaker H bonding?

NH bond is less polar than OH

What allows amines to be basic and nucleophiles?

the lone pair on the nitrogen

Why are amine drugs given as salts?

amine salts are more soluble in water than amines, so they can dissolve better in body fluids.

What does a higher pKa mean?

weaker acid and stronger conjugate base.

What is the general pattern of basicity in amines?

the greater the availability of the lone pair, the greater the base strength

Why are aromatic amines less basic?

N lone pair is delocalised in aromatic ring so less able to accept H+

What is the strongest base among neutral organic compounds?

guanidine

are amides also proton acceptors?

no

What is produced when amines react with carboxylic acid derivatives?

amides and acid

What is produced when amines react with sulfonyl chloride?

sulphonamides