Carboxylic acids RCOOH.
Links
Carboxylic acid
→ ester
Reagents: alcohol and a little concentrated
sulphuric acid catalyst
Conditions: heat under reflux
This is an equilibrium reaction.
CH3COOH + CH3CH2OH 
CH3COOCH2CH3 + H2O
Alkanes
& alkenes
Arenes
Halogenoalkanes
Alcohols
Aldehydes and
ketones
Carboxylic acids
Acyl chlorides
Amines
Nitro compounds
Nitriles
Amides
Ester hydrolysis
(equilibrium)
Reagents: dilute sulphuric acid
Conditions: heat under reflux
This gives an equilibrium mixture:
CH3COOCH2CH3 + H2O
CH3COOH + CH3CH2OH
Ester hydrolysis
(non-equilibrium)
Reagents: dilute aqueous sodium
hydroxide
Conditions: heat under reflux
This gives complete hydrolysis to the sodium salt of the acid. The free acid is formed by acidification with dilute hydrochloric acid, which is a stronger acid than the carboxylic acid:
CH3COOCH2CH3 + NaOH → CH3COO- Na+ + CH3CH2OH
CH3COO- Na+ + HCl → CH3COOH + NaCl
Carboxylic acid
(as its ester)
→ alcohol
Reagents: lithium aluminium hydride,
followed by water.
Conditions: Direct reduction of the
acids is difficult, and they are usually converted into an ester first. This is then
heated under reflux with lithium aluminium hydride in dry ether, the mixture cooled, and
followed by the cautious addition of water in the fume cupboard since hydrogen is evolved.
The reducing agent can be indicated by [H] in this case.
CH3CH2COOCH2CH3 + 4[H] " CH3CH2CH2OH + HOCH2CH3
Carboxylic acid
→ acid (acyl) chloride
Reagents: phosphorus pentachloride
Conditions: r.t.
CH3COOH + PCl5 → CH3COCl + HCl + POCl3