MedChem 18

Amines

Organic relatives of NH₃ obtained by replacing one, two or three H with organic

How are amines classified

As primary, secondary and tertiary

What is the classification of amine based on

Degree of substitution at the N atom

What charge does N carry in amine

Positive charge

Geometry of amines

Tetrahedral

BP of amines

Higher than alkanes

What bonds do amines have

H bonds

What is the chemistry of amine determined by

Lone pair of e- on N

Acidity / basicness of amines

Basic amines react with acids to form salts

Nucleophilicity / electrophilicity of amines

Amines react with eelctrophiles

EDG of N

Increase basicity of amines

Push e- density towards N

Making it easier to accept a proton and therefore a better base

EWG decrease basicity of amines

Pull e- density away from N
Making it less easy to accept a proton and therefore a poorer base

Basicity of aromatic amines

Lone pairs of e- on N in aniline interacts with the aromatic sextet and is not as available as the lone pair in aliphatic amines

Nucleophilicity of amines

Lone pairs of e- on nitrogen gives amines basic and nucleophilic properties

What are amines

Organic derivatives of ammonia

How do you synthesis amines

synthesised from ammonia

How are quaternary ammonium salts formed

Rxn of a tertiary amine with an alkyl halide

How does alkylation of ammonia/ amines occur

By Sn2 rxn produces a mixture of products

Ammonnia + aldehydes/ ketones ->

Imines

Reduction of imines

By amines

Using a reducing agent

Imines

Intermediates in the biosynthesis of several amine acids

Amino acid contains

Amino and a carboxylic acid

essential acids

Biosynthesized only in plants and microorganisms

How do imines react

As electrophiles

What do imines react with

Carbonyl carbons

Amine drugs

Lipophilic and poorly soluble in blood plasma

How do you administer amine drugs

Hydrochloride salts

What does administering drugs as hydrochloride salts do

Make them water soluble