Chapter 27

• Compounds derived from ammonia, where one or more of the H atoms are replaced by a carbon chain

• Primary, secondary and tertiary • Aliphatic or aromatic

• In aliphatic amines the N atom is attached to at least one straight or branched carbon chain • In aromatic amines the N atom is attached to an aromatic ring

• A primary amine is bonded to 1 alkyl or aryl groups • A secondary amine is bonded to 2 • A tertiary amine is bonded to 3

• If the amine is at the end of the chain, you add the suffix -amine (e.g. ethylamine) • If the amine is not on carbon 1, you use the prefix amino- (e.g. 2-aminobutane)

• If they’re attached to multiples of the same alkyl chain, you use the prefix di- or tri- (e.g. dimethylamine) • If they’re attached to different alkyl chains, use the short one as a prefix (if there are 2 other chains, put them in alphabetical order) and add an N to show that the other chain is also bonded to the nitrogen atom (e.g. N-methylpropylamine, N-ethyl-N-methylpropylamine, N,N-dimethylethylamine)

• Weak bases, as the lone pair on the N atom can accept a proton and form a dative covalent bond • Nucleophiles, as there is a lone pair of electrons on the N atom

• They form an ammonium salt • Hydrochloric acid + propylamine -> propylammonium chloride

• Salt formation: reacting a haloalkane with ammonia to form an ammonium salt • Amine formation: reacting the ammonium salt with sodium hydroxide to form the primary amine

• To form secondary amines, the process to form primary amines repeats, but with a primary amine taking the role of ammonia (the N still has a lone pair) • To form tertiary amines, secondary amines are reacted with a haloalkane

• Step 1: nucleophilic substitution • Excess ethanolic ammonia • 1-chloropropane + ammonia -> propylammonium chloride • Step 2: check mechanism • propylammonium chloride + sodium hydroxide -> amine + sodium chloride + water

• Ethanol is used as a solvent instead of water, as otherwise the haloalkane would react with water via nucleophilic substitution to form an alcohol • Excess ammonia is used to reduce (although it’s not possible to entirely avoid) further substitution of the amine to form secondary and tertiary amines

• Nitrobenzene is reduced using tin and concentrated hydrochloric acid

• Nitrobenzene + 6[H] -> phenylamine + 2H2O • Conditions: Sn and concentrated HCl

• Compounds with an amine group on one end, and a carboxyl group on the other

• They only have one central carbon atom which has a H group, and an R group • The R group is what differs between them

• The amine group reacts to form an ammonium salt (NH3+X)

• The carboxyl group reacts to form a carboxylate salt and water

• If an amino acid is heated under reflux with an acid catalyst, it forms an ester and water • The amine group is also protonated due to the acidic conditions

• A type of stereoisomerism

• Stereoisomers that are non-superimposable mirror images of each other (think hands) • (Superimposable: can perfectly overlap if they are in the same place) • The pair are called enantiomers

• One or more chiral centres in a molecule

• Chiral centres are usually carbon atoms that are bonded to 4 other groups; this makes them asymmetric (if it was bonded to less than 4 groups, or 2 or more of the same group, you can split the molecule in half and it would look the same)

• Number of enantiomers: 2^n • n: number of chiral centres