Unit 4.6 Amines

A compound containing a nitrogen atom with a lone pair of electrons.

A carboxylic acid where the OH has been substituted for an $NH_2$ ($CONH_2$)

1.) Nucleophilic substitution of a halogenoalkane. The halogenoalkane is heated with a concentrated solution of ethanolic ammonia in a sealed tube. The product must then be treated with NaOH to reduce the amine salt to the amine.

2.) Reduction of a hydroxynitrile. This is done dry using lithium tetrahydridoaluminate as a very strong reducing agent is required. The product must then be treated with a dilute acid.

Primary, secondary, tertiary, and quaterrnary amines and their salts are formed, requiring additional purification steps.

Aromatic amines can be formed through the reduction of nitrobenzenes. This is done using concentrated hydrochloric acid and tin, heated under reflux. The aminobenzene salt is formed, which must be treated with dilute NaOH to form the desired product. The final product is the aminobenzene, plus a mixture of various tin compounds.

Amines are basic in nature, as their lone pair allows them to act as a proton acceptor. They are also nucleophilic

Aromatic amines are less basic than ammonia as the lone pair of electrons on the nitrogen overlap with the pi electron cloud of the benzene. Aliphatic amines are more basic than ammonia, as the carbon chain can shuttle electrons to stabilise the charge

A condensation reaction (addition-elimination)

An N-substituted amide and ammonium chloride

An amide where a hydrogen off of the nitrogen has been substituted for an R group

Ethanoylation

Phenylamine or aniline

Using nitric iii acid, $HNO_2$. An amine will result in

Bromoalkanes are normaly used due to their balance between being electronegative enough to form a dipole susceptible to nucleophilic attack, and ease of leaving.