Reflux the carboxylic acid with an excess of the alcohol (or the alcohol with an excess of the carboxylic acid) with about 3–5% of a mineral acid (usually HCl or H₂SO₄) as a catalyst and distil out the water that is formed in the reaction. For example, butanol was heated under reflux with a fourfold excess of acetic acid and a catalytic amount of concentrated H₂SO₄ to give butyl acetate in a yield of 70%.

It may also help to distil out the water that is formed in the reaction: diethyl adipate (the diethyl ester of hexanedioic acid) can be made in toluene solution using a sixfold excess of ethanol, concentrated H₂SO₄ as catalyst, heating in toluene, and distilling out the water using a Dean Stark apparatus. You can tell from the yield that the equilibrium is very favourable.

In these cases, the equilibrium is made more favourable by using an excess of reagents and/ or removing one of the products. The equilibrium constant remains the same.

مواضيع ذات صلة

Energy, enthalpy, and entropy: ΔG, ΔH, and ΔS

How to make the equilibrium favour the product you want The direct formation of esters

A small change in ΔG makes a big difference in K

The sign of ΔG tells us whether products or reactants are favoured at equilibrium

How the equilibrium constant varies with the difference in energy between reactants and products

Stability and energy levels

Substitution of C=O for C=C: a brief look at the Wittig reaction

Cyanide will attack iminium ions: the Strecker synthesis of amino acids

Lithium aluminium hydride reduces amides to amines

Iminium ions can react as electrophilic intermediates

Secondary amines react with carbonyl compounds to form enamines

Iminium ions and oxonium ions