The Knoevenagel reaction as another condensation possessing, it has a mechanism similar to that of the condensation of the aldol reaction. The Knoevenagel reaction in its simplest form is the condensation of malonic esters (or their analogues) with aldehydes or ketones in the presence of an amine-base catalyst plus a small amount of carboxylic acid (or amino acid) cocatalyst. The condensation products are often a,B-unsaturated carbonyl compounds. For example